The DTB expects the correct PC in the ThreadContext
but how if the memory accesses are speculative? Shouldn't
we send along the requestor's PC to the translate functions?
if a faulting instruction reaches an execution unit,
then ignore it and pass it through the pipeline.
Once we recognize the fault in the graduation unit,
dont allow a second fault to creep in on the same cycle.
Before graduating an instruction, explicitly check fault
by making the fault check it's own separate command
that can be put on an instruction schedule.
this always changes the PC and is basically an impromptu branch instruction. why
not speculate on this instead of always be forced to mispredict/squash after the
hwrei gets resolved?
The InOrder model needs this marked as "isControl" so it knows to update the PC
after the ALU executes it. If this isnt marked as control, then it's going to
force the model to check the PC of every instruction at commit (what O3 does?),
and that would be a wasteful check for a very high percentage of instructions.
remove events in the resource pool that can be called from the CPU event, since the CPU
event is scheduled at the same time at the resource pool event.
----
Also, match the resPool event function names to the cpu event function names
----
only update BTB on a taken branch and update branch predictor w/pcstate from instruction
---
only pay attention to branch predictor updates if the the inst. is in fact a branch
formerly, this was implicit when you accessed the execution unit
or the use-def unit but it's better that this just be something
that a user can specify.
Architectures like SPARC need to read the window pointer
in order to figure out it's register dependence. However,
this may not get updated until after an instruction gets
executed, so now we lazily detect the register dependence
in the EXE stage (execution unit or use_def). This
makes sure we get the mapping after the most current change.
Instead of clearing the entire TLB on initialization and flush, the code was
clearing only one element. This patch corrects the memsets in the init and
flush routines.
The code for Set class was written under the assumption that
std::numeric_limits<long>::digits returns the number of bits used for
data type long, which was presumed to be either 32 or 64. But return value
is actually one less, that is, it is either 31 or 63. The value is now
being incremented by 1 so as to correctly set it.
If there's a problem when reading the section names from a supposed ELF file,
this change makes gem5 print an error message as returned by libelf and die.
Previously these sorts of errors would make gem5 segfault when it tried to
access the section name through a NULL pointer.
this flag is only used for early branch resolution in the O3 model (of pc-relative branches)
but this isnt cleanly working even when the branch target code is added for sparc. For now,
we'll ignore this optimization and add a todo in the SPARC ISA for future developers
Add a few constants and functions that the InOrder model wants for SPARC.
* * *
sparc: add eaComp function
InOrder separates the address generation from the actual access so give
Sparc that functionality
* * *
sparc: add control flags for branches
branch predictors and other cpu model functions need to know specific information
about branches, so add the necessary flags here
The access permissions for the directory entries are not being set correctly.
This is because pointers are not used for handling directory entries.
function. get and set functions for access permissions have been added to the
Controller state machine. The changePermission() function provided by the
AbstractEntry and AbstractCacheEntry classes has been exposed to SLICC
code once again. The set_permission() functionality has been removed.
NOTE: Each protocol will have to define these get and set functions in order
to compile successfully.
The regular expressions matching filenames in the ##include directives and the
internally generated ##newfile directives where only looking for filenames
composed of alpha numeric characters, periods, and dashes. In Unix/Linux, the
rules for what characters can be in a filename are much looser than that. This
change replaces those expressions with ones that look for anything other than
a quote character. Technically quote characters are allowed as well so we
should allow escaping them somehow, but the additional complexity probably
isn't worth it.
Currently, the machine name is appended before any of the functions
defined with in the sm files. This is not necessary and it also
means that these functions cannot be used outside the sm files.
This patch does away with the prefixes. Note that the generated
C++ files in which the code for these functions is present are
still named such that the machine name is the prefix.
The default generated binary is now gem5.<type> instead of m5.<type>.
The latter does still work but gem5.<type> will be generated first and
then m5.<type> will be hard linked to it.
The end of the COPYING file was generated with:
% python ./util/find_copyrights.py configs src system tests util
Update -C command line option to spit out COPYING file
We were getting a spurious warning in the regressions that turned
out to be due to having the wrong value for TGT_MAP_ANONYMOUS for
Power Linux, but in the process of tracking it down I ended up
doing some cleanup of the mmap handling in general.
A significant contributor to the need for adoptOrphanParams()
is the practice of appending to SimObjectVectors which have
already been assigned as children. This practice sidesteps the
assignment operation for those appended SimObjects, which is
where parent/child relationships are typically established.
This patch reworks the config scripts that use append() on
SimObjectVectors, which all happen to be in the x86 system
configuration. At some point in the future, I hope to make
SimObjectVectors immutable (by deriving from tuple rather than
list), at which time this patch will be necessary for correct
operation. For now, it just avoids some of the warning
messages that get printed in adoptOrphanParams().
Re-enabling implicit parenting (see previous patch) causes current
Ruby config scripts to create some strange hierarchies and generate
several warnings. This patch makes three general changes to address
these issues.
1. The order of object creation in the ruby config files makes the L1
caches children of the sequencer rather than the controller; these
config ciles are rewritten to assign the L1 caches to the
controller first.
2. The assignment of the sequencer list to system.ruby.cpu_ruby_ports
causes the sequencers to be children of system.ruby, generating
warnings because they are already parented to their respective
controllers. Changing this attribute to _cpu_ruby_ports fixes this
because the leading underscore means this is now treated as a plain
Python attribute rather than a child assignment. As a result, the
configuration hierarchy changes such that, e.g.,
system.ruby.cpu_ruby_ports0 becomes system.l1_cntrl0.sequencer.
3. In the topology classes, the routers become children of some random
internal link node rather than direct children of the topology.
The topology classes are rewritten to assign the routers to the
topology object first.
Last summer's big rewrite of the initialization code (in
particular cset 6efc3672733b) got rid of the implicit parenting
that used to occur when an unparented SimObject was assigned as
a parameter value to another SimObject. The idea was that the
new adoptOrphanParams() step would catch these anyway so it was
unnecessary.
Unfortunately it turns out that adoptOrphanParams() has some
inherent instability in that the parent that does the adoption
depends on the config tree traversal order. Even making this
order deterministic (e.g., by traversing children in
alphabetical order) can introduce unwanted and unexpected
hierarchy changes between similar configs (e.g., when adding a
switch_cpu in place of a cpu), causing problems when trying to
restore checkpoints across similar configs. The hierarchy
created by implicit parenting is more stable and more
controllable, so this patch turns that behavior back on.
This patch also cleans up some long-standing holes regarding
parenting of SimObjects that are created in class definitions
(either in the body of the class, or as default parameters).
To avoid breaking some existing config files, this necessitated
changing the error on reparenting children to a warning. This
change fixes another bug where attempting to print the prior
error message would fail on reparenting SimObjectVectors
because they lack a _parent attribute. Some further issues
with SimObjectVectors were cleaned up by getting rid of the
get_parent() call (which could cause errors with some
SimObjectVectors where there was no single parent to return)
with has_parent() (since all the uses of get_parent() were just
boolean tests anyway).
Finally, since the adoptOrphanParam() step turned out to be so
problematic, we now issue a warning when it actually has to do
an adoption. Future cleanup of config files will get rid of
current warnings.
Calculation of offset to copy from storeQueue[idx].data structure for load to
store forwarding fixed to be difference in bytes between store and load virtual
addresses. Previous method would induce bug where a load would index into
buffer at the wrong location.
If a split load fails on a blocked cache wbOutstanding can be decremented
twice if the first part of the split load succeeds and the second part fails.
Condition the decrementing on not having completed the first part of the load.
This patch fixes two problems with the O3 cpu model. The first is an issue
with an instruction fetch causing a fault on the next address while the
current macro-op is being issued. This happens when the micro-ops exceed
the fetch bandwdith and then on the next cycle the fetch stage attempts
to issue a request to the next line while it still has micro-ops to issue
if the next line faults a fault is attached to a micro-op in the currently
executing macro-op rather than a "nop" from the next instruction block.
This leads to an instruction incorrectly faulting when on fetch when
it had no reason to fault.
A similar problem occurs with interrupts. When an interrupt occurs the
fetch stage nominally stops issuing instructions immediately. This is incorrect
in the case of a macro-op as the current location might not be interruptable.
The virtual channels within "response" vnets are made buffers_per_data_vc
deep (default=4), while virtual channels within other vnets are made
buffers_per_ctrl_vc deep (default = 1). This is for accurate power estimates.
Identifying response vnets versus other vnets will allow garnet to
determine which vnets will carry data packets, and which will carry
ctrl packets, and use appropriate buffer sizes (since data packets are larger
than ctrl packets). This in turn allows the orion power model to accurately
estimate buffer power.
Renamed (message) class to vnet for consistency with rest of ruby.
Moved some parameters specific to fixed/flexible garnet networks into their
corresponding py files.
This change further eliminates cases where condition codes were being read
just so they could be written without change because the instruction in
question was supposed to preserve them. This is done by creating the condition
code code based on the input rather than just doing a simple substitution.
If one of the condition codes isn't being used in the execution we should only
read it if the instruction might be dependent on it. With the preeceding changes
there are several more cases where we should dynamically pick instead of assuming
as we did before.
Break up the condition code bits into NZ, C, V registers. These are individually
written and this removes some incorrect dependencies between instructions.
Move the saturating bit (which is also saturating) from the renamed register
that holds the flags to the CPSR miscreg and adds a allows setting it in a
similar way to the FP saturating registers. This removes a dependency in
instructions that don't write, but need to preserve the Q bit.
This change splits out the condcodes from being one monolithic register
into three blocks that are updated independently. This allows CPUs
to not have to do RMW operations on the flags registers for instructions
that don't write all flags.
Debug flags are ExecUser, ExecKernel, and ExecAsid. ExecUser and
ExecKernel are set by default when Exec is specified. Use minus
sign with ExecUser or ExecKernel to remove user or kernel tracing
respectively.
Add registers and components to better support the VersatileEB board.
Made the MIDR and SYS_ID register parameters to ArmSystem and RealviewCtrl
respectively.
Instructions that load an address and are control instructions can
execute down the wrong path if they were predicted correctly and then
instructions following them are squashed. If an instruction is a
memory and control op use the predicted address for the next PC instead
of just advancing the PC. Without this change NPC is used for the next
instruction, but predPC is used to verify that the branch was successful
so the wrong path is silently executed.
The network tester terminates after injecting for sim_cycles
(default=1000), instead of having to explicitly pass --maxticks from the
command line as before. If fixed_pkts is enabled, the tester only
injects maxpackets number of packets, else it keeps injecting till sim_cycles.
The tester also works with zero command line arguments now.
The RubyMemory flag wasnt used in the code, creating large gaps in trace output. Replace cprintfs w/dprintfs
using RubyMemory in memory controller. DPRINTF also deprecate the usage of the setDebug() pure virtual
function in the AbstractMemoryOrCache Class as well the m_debug/cprintf functions in MemoryControl.hh/cc
The simple network's endpoint bandwidth value is used to adjust the overall
bandwidth of the network. Specifically, the ration between endpoint bandwidth
and the MESSAGE_SIZE_MULTIPLIER determines the increase. By setting the value
to 1000, that means the bandwdith factor specified in the links translates to
the link bandwidth in bytes. Previously, it was increasing that value by 10.
This patch will likely require a reset of the ruby regression tester stats.
Moved the buffer_size, endpoint_bandwidth, and adaptive_routing params out of
the top-level parent network object and to only those networks that actually
use those parameters.
This patch ensures that both Garnet and the simple networks use the bw value
specified in the topology. To do so, the patch generalizes the specification
of bw for basic links. This value is then translated to the specific value
used by the simple and Garnet networks. Since Garent does not support
non-uniformed link bandwidth, the patch also adds a check to ensure all bws are
equal.
--HG--
rename : src/mem/ruby/network/BasicLink.cc => src/mem/ruby/network/simple/SimpleLink.cc
rename : src/mem/ruby/network/BasicLink.hh => src/mem/ruby/network/simple/SimpleLink.hh
rename : src/mem/ruby/network/BasicLink.py => src/mem/ruby/network/simple/SimpleLink.py
This patch converts links and switches from second class simobjects that were
virtually ignored by the networks (both simple and Garnet) to first class
simobjects that directly correspond to c++ ojbects manipulated by the
topology and network classes. This is especially true for Garnet, where the
links and switches directly correspond to specific C++ objects.
By making this change, many aspects of the Topology class were simplified.
--HG--
rename : src/mem/ruby/network/Network.cc => src/mem/ruby/network/BasicLink.cc
rename : src/mem/ruby/network/Network.hh => src/mem/ruby/network/BasicLink.hh
rename : src/mem/ruby/network/Network.cc => src/mem/ruby/network/garnet/fixed-pipeline/GarnetLink_d.cc
rename : src/mem/ruby/network/Network.hh => src/mem/ruby/network/garnet/fixed-pipeline/GarnetLink_d.hh
rename : src/mem/ruby/network/garnet/fixed-pipeline/GarnetNetwork_d.py => src/mem/ruby/network/garnet/fixed-pipeline/GarnetLink_d.py
rename : src/mem/ruby/network/garnet/fixed-pipeline/GarnetNetwork_d.py => src/mem/ruby/network/garnet/fixed-pipeline/GarnetRouter_d.py
rename : src/mem/ruby/network/Network.cc => src/mem/ruby/network/garnet/flexible-pipeline/GarnetLink.cc
rename : src/mem/ruby/network/Network.hh => src/mem/ruby/network/garnet/flexible-pipeline/GarnetLink.hh
rename : src/mem/ruby/network/garnet/fixed-pipeline/GarnetNetwork_d.py => src/mem/ruby/network/garnet/flexible-pipeline/GarnetLink.py
rename : src/mem/ruby/network/garnet/fixed-pipeline/GarnetNetwork_d.py => src/mem/ruby/network/garnet/flexible-pipeline/GarnetRouter.py
Moved the Topology class to the top network directory because it is shared by
both the simple and Garnet networks.
--HG--
rename : src/mem/ruby/network/simple/Topology.cc => src/mem/ruby/network/Topology.cc
rename : src/mem/ruby/network/simple/Topology.hh => src/mem/ruby/network/Topology.hh
Due to certain changes made via changeset 8229, the compilation was failing
in certain cases. The compiler pointed to base/stats/mysql.hh for not naming
a certain types like uint64_t. To rectify this, base/types.hh is being
included in base/stats/mysql.hh.
This change makes the decoder figure out if an instruction that only supports
memory is using a register encoding and decodes directly to "Unknown" which will
behave appropriately. This prevents other parts of the instruction creation
process from seeing the mismatch and asserting.
This is similar to guards on mercurial queues and they're used for selecting
which files are compiled into some given object. We already do something
similar, but it's mostly hard coded for the m5 binary and the m5 library
and I'd like to make it more flexible to better support the unittests
At the same time, rename the trace flags to debug flags since they
have broader usage than simply tracing. This means that
--trace-flags is now --debug-flags and --trace-help is now --debug-help
This is basically like the range_map stuff in src/base (range already
exists in Python). This code is like a set of ranges. I'm using it
to keep track of changed lines in source code, but it could be use to
keep track of memory ranges and holes in memory regions. It could
also be used in memory allocation type stuff. (Though it's not at all
optimized.)
Frame buffer and boot linux:
./build/ARM_FS/m5.opt configs/example/fs.py --benchmark=ArmLinuxFrameBuf --kernel=vmlinux.touchkit
Linux from a CF card:
./build/ARM_FS/m5.opt configs/example/fs.py --benchmark=ArmLinuxCflash --kernel=vmlinux.touchkit
Run Android
./build/ARM_FS/m5.opt configs/example/fs.py --benchmark=ArmAndroid --kernel=vmlinux.android
Run MP
./build/ARM_FS/m5.opt configs/example/fs.py --benchmark=ArmLinuxCflash --kernel=vmlinux.mp-2.6.38
This change fixes a small bug in the arm copyRegs() code where some registers
wouldn't be copied if the processor was in a mode other than MODE_USER.
Additionally, this change simplifies the way the O3 switchCpu code works by
utilizing TheISA::copyRegs() to copy the required context information
rather than the adhoc copying that goes on in the CPU model. The current code
makes assumptions about the visibility of int and float registers that aren't
true for all architectures in FS mode.
The comment in the code suggests that the checking granularity should be 16
bytes, however in reality the shift by 8 is 256 bytes which seems much
larger than required.
Fixed an error reguarding DMA for uninprocessor systems. Basically removed an
overly agressive optimization that lead to inconsistent state between the
cache and the directory.
This function duplicates the functionality of allocate() exactly, except that it does not return
a return value. In protocols where you just want to allocate a block
but do not want that block to be your implicitly passed cache_entry, use this function.
Otherwise, SLICC will complain if you do not consume the pointer returned by allocate(),
and if you do a dummy assignment Entry foo := cache.allocate(address), the C++
compiler will complain of an unused variable. This is kind of a hack to get around
those issues, but suggestions welcome.
Before this changeset, all local variables of type Entry and TBE were considered
to be pointers, but an immediate use of said variables would not be automatically
deferenced in SLICC-generated code. Instead, deferences occurred when such
variables were passed to functions, and were automatically dereferenced in
the bodies of the functions (e.g. the implicitly passed cache_entry).
This is a more general way to do it, which leaves in place the
assumption that parameters to functions and local variables of type AbstractCacheEntry
and TBE are always pointers, but instead of dereferencing to access member variables
on a contextual basis, the dereferencing automatically occurs on a type basis at the
moment a member is being accessed. So, now, things you can do that you couldn't before
include:
Entry foo := getCacheEntry(address);
cache_entry.DataBlk := foo.DataBlk;
or
cache_entry.DataBlk := getCacheEntry(address).DataBlk;
or even
cache_entry.DataBlk := static_cast(Entry, pointer, cache.lookup(address)).DataBlk;
This is a substitute for MessageBuffers between controllers where you don't
want messages to actually go through the Network, because requests/responses can
always get reordered wrt to one another (even if you turn off Randomization and turn on Ordered)
because you are, after all, going through a network with contention. For systems where you model
multiple controllers that are very tightly coupled and do not actually go through a network,
it is a pain to have to write a coherence protocol to account for mixed up request/response orderings
despite the fact that it's completely unrealistic. This is *not* meant as a substitute for real
MessageBuffers when messages do in fact go over a network.
It is useful for Ruby to understand from whence request packets came.
This has all request packets going into Ruby pass the contextId value, if
it exists. This supplants the old libruby proc_id value passed around in
all the Messages, so I've also removed the unused unsigned proc_id; member
generated by SLICC for all Message types.
***
(1): get rid of expandForMT function
MIPS is the only ISA that cares about having a piece of ISA state integrate
multiple threads so add constants for MIPS and relieve the other ISAs from having
to define this. Also, InOrder was the only core that was actively calling
this function
* * *
(2): get rid of corespecific type
The CoreSpecific type was used as a proxy to pass in HW specific params to
a MIPS CPU, but since MIPS FS hasnt been touched for awhile, it makes sense
to not force every other ISA to use CoreSpecific as well use a special
reset function to set it. That probably should go in a PowerOn reset fault
anyway.
The goal of the patch is to do away with the CacheMsg class currently in use
in coherence protocols. In place of CacheMsg, the RubyRequest class will used.
This class is already present in slicc_interface/RubyRequest.hh. In fact,
objects of class CacheMsg are generated by copying values from a RubyRequest
object.
The tester code is in testers/networktest.
The tester can be invoked by configs/example/ruby_network_test.py.
A dummy coherence protocol called Network_test is also addded for network-only simulations and testing. The protocol takes in messages from the tester and just pushes them into the network in the appropriate vnet, without storing any state.
I had recently committed a patch that removed the WakeUp*.py files from the
slicc/ast directory. I had forgotten to remove the import calls for these
files from slicc/ast/__init__.py. This resulted in error while running
regressions on zizzer. This patch does the needful.
This patch fixes the problem where Ruby would fail to call sendRetry on ports
after it nacked the port. This patch is particularly helpful for bursty dma
requests which often include several packets.
In SLICC, in order to define a type a data type for which it should not
generate any code, the keyword external_type is used. For those data types for
which code should be generated, the keyword structure is used. This patch
eliminates the use of keyword external_type for defining structures. structure
key word can now have an optional attribute external, which would be used for
figuring out whether or not to generate the code for this structure. Also, now
structures can have functions as well data members in them.
In order to add stall and wait facility for protocols, a keyword
wake_up_dependents was introduced. This patch removes the keyword,
instead this functionality is now implemented as function call.
In order to add stall and wait facility for protocols, a keyword
wake_up_all_dependents was introduced. This patch removes the keyword,
instead this functionality is now implemented as function call.
Thanks to swig this was interfering with the standard Python
random module. The only function in that module was seed(),
which erroneously called srand48(). Moved the function to
m5.internal.core, renamed it seedRandom(), and made it call
random_mt.init() instead.
FastAlloc's reuse policies can mask allocation bugs, so
we typically want it disabled when debugging. Set
FORCE_FAST_ALLOC to enable even when debugging, and set
NO_FAST_ALLOC to disable even in non-debug builds.
The ISAR registers describe which features the processor supports.
Transcribe the values listed in section B5.2.5 of the ARM ARM
into the registers as read-only values
This change speeds up booting, especially in MP cases, by not executing
udelay() on the core but instead skipping ahead tha amount of time that is being
delayed.
This patch prevents not executed conditional instructions marked as
IsQuiesce from stalling the pipeline indefinitely. If the instruction
is not executed the quiesceSkip psuedoinst is called which schedules a
wakes up call to the fetch stage.
This changes the RFE macroop into 3 microops:
URa = [sp]; URb = [sp+4]; // load CPSR,PC values from stack
sp = sp + offset; // optionally auto-increment
PC = URa; CPSR = URb; // write to the PC and CPSR.
Importantly:
- writing to PC is handled in the last micro-op.
- loading occurs prior to state changes.
This change fixes the problem for all the cases we actively use. If you want to try
more creative I/O device attachments (E.g. sharing an L2), this won't work. You
would need another level of caching between the I/O device and the cache
(which you actually need anyway with our current code to make sure writes
propagate). This is required so that you can mark the cache in between as
top level and it won't try to send ownership of a block to the I/O device.
Asserts have been added that should catch any issues.
Without this change the a store can be issued to the cache multiple times.
If this case occurs when the l1 cache is out of mshrs (and thus blocked)
the processor will never make forward progress because each cycle it will
send a single request using the recently freed mshr and not completing the
multipart store. This will continue forever.
This causes a lot of rebuilds that could have otherwise possibly been
avoided, and, more annoyingly, a lot of unnecessary rerunning of the
regressions. The benefits of having the revision in the output haven't
materialized, so this change removes it.
None of the code in the ruby tester directory is compiled or referred to
outside of that directory. This change eliminates it. If it's needed in the
future, it can be revived from the history. In the mean time, this removes
clutter and the only use of the GEMS_ROOT scons variable.
The internet says this instruction was created by accident when an Intel CPU
failed to decode x87 instructions properly. It's been documented on a few rare
occasions and has generally worked to ensure backwards compatability. One
source claims that the gcc toolchain is basically the only thing that emits
it, and that emulators/binary translators like qemu and bochs implement it.
We won't actually implement it here since we're hardly implementing any other
x87 instructions either. If we were to implement it, it would behave the same
as ffree but then also pop the register stack.
http://www.pagetable.com/?p=16
There may not be a formally correct spelling for the past tense of mmap, but
mmapped is the spelling Google doesn't try to autocorrect. This makes sense
because it mirrors the past tense of map->mapped and not the past tense of
cape->caped.
--HG--
rename : src/arch/alpha/mmaped_ipr.hh => src/arch/alpha/mmapped_ipr.hh
rename : src/arch/arm/mmaped_ipr.hh => src/arch/arm/mmapped_ipr.hh
rename : src/arch/mips/mmaped_ipr.hh => src/arch/mips/mmapped_ipr.hh
rename : src/arch/power/mmaped_ipr.hh => src/arch/power/mmapped_ipr.hh
rename : src/arch/sparc/mmaped_ipr.hh => src/arch/sparc/mmapped_ipr.hh
rename : src/arch/x86/mmaped_ipr.hh => src/arch/x86/mmapped_ipr.hh
At a couple of places in PerfectSwitch.cc and MessageBuffer.cc, DPRINTF()
has not been provided with correct number of arguments. The patch fixes these
bugs.
This patch removes the store buffer from Ruby. It is not in use currently.
Since libruby is being and store buffer makes calls to libruby, it is not
possible to maintain it until substantial changes are made.
This patch changes Address.hh so that it is not dependent on RubySystem.
This dependence seems unecessary. All those functions that depend on
RubySystem have been moved to Address.cc file.
This patch changes DataBlock.hh so that it is not dependent on RubySystem.
This dependence seems unecessary. All those functions that depende on
RubySystem have been moved to DataBlock.cc file.
This patch integrates permissions with cache and memory states, and then
automates the setting of permissions within the generated code. No longer
does one need to manually set the permissions within the setState funciton.
This patch will faciliate easier functional access support by always correctly
setting permissions for both cache and memory states.
--HG--
rename : src/mem/slicc/ast/EnumDeclAST.py => src/mem/slicc/ast/StateDeclAST.py
rename : src/mem/slicc/ast/TypeFieldEnumAST.py => src/mem/slicc/ast/TypeFieldStateAST.py
Because int and not InstSeqNum was used in a couple of places, you can
overflow the int type and thus get wierd bugs when the sequence number
is negative (or some wierd value)
remove constructors that werent being used (it just gets confusing)
use initialization list for all the variables instead of relying on initVars()
function
-use a pointer to CacheReqPacket instead of PacketPtr so correct destructors
get called on packet deletion
- make sure to delete the packet if the cache blocks the sendTiming request
or for some reason we dont use the packet
- dont overwrite memory requests since in the worst case an instruction will
be replaying a request so no need to keep allocating a new request
- we dont use retryPkt so delete it
- fetch code was split out already, so just assert that this is a memory
reference inst. and that the staticInst is available
If there is an outstanding table walk and no other activity in the CPU
it can go to sleep and never wake up. This change makes the instruction
queue always active if the CPU is waiting for a store to translate.
If Gabe changes the way this code works then the below should be removed
as indicated by the todo.
We only support EABI binaries, so there is no reason to support OABI syscalls.
The loader detects OABI calls and fatal() so there is no reason to even check
here.
The ARM performance counters are not currently supported by the model.
This patch interprets a 'reset performance counters' command to mean 'reset
the simulator statistics' instead.
"executing" isnt a very descriptive debug message and in going through the
output you get multiple messages that say "executing" but nothing to help
you parse through the code/execution.
So instead, at least print out the name of the action that is taking
place in these functions.
Overall, continue to progress Ruby debug messages to more of the normal M5
debug message style
- add a name() to the Ruby Throttle & PerfectSwitch objects so that the debug output
isn't littered w/"global:" everywhere.
- clean up messages that print over multiple lines when possible
- clean up duplicate prints in the message buffer
In certain actions of the L1 cache controller, while creating an outgoing
message, the machine type was not being set. This results in a
segmentation fault when trace is collected. Joseph Pusudesris provided
his patch for fixing this issue.
keep track of when an instruction needs the execution
behind it to be serialized. Without this, in SE Mode
instructions can execute behind a system call exit().
resources don't need to call getLatency because the latency is already a member
in the class. If there is some type of special case where different instructions
impose a different latency inside a resource then we can revisit this and
add getLatency() back in
each resource has a certain # of requests it can take per cycle. update the #s here
to be more realistic based off of the pipeline width and if the resource needs to
be accessed on multiple cycles
---
need to delete the cache request's data on clearRequest() now that we are recycling
requests
---
fetch unit needs to deallocate the fetch buffer blocks when they are replaced or
squashed.
formerly, to free up bandwidth in a resource, we could just change the pointer in that resource
but at the same time the pipeline stages had visibility to see what happened to a resource request.
Now that we are recycling these requests (to avoid too much dynamic allocation), we can't throw
away the request too early or the pipeline stage gets bad information. Instead, mark when a request
is done with the resource all together and then let the pipeline stage call back to the resource
that it's time to free up the bandwidth for more instructions
*** inteface notes ***
- When an instruction completes and is done in a resource for that cycle, call done()
- When an instruction fails and is done with a resource for that cycle, call done(false)
- When an instruction completes, but isnt finished with a resource, call completed()
- When an instruction fails, but isnt finished with a resource, call completed(false)
* * *
inorder: tlbmiss wakeup bug fix
take away all instances of reqMap in the code and make all references use the built-in
request vectors inside of each resource. The request map was dynamically allocating
a request per instruction. The request vector just allocates N number of requests
during instantiation and then the surrounding code is fixed up to reuse those N requests
***
setRequest() and clearRequest() are the new accessors needed to define a new
request in a resource
we are going to be getting away from creating new resource requests for every
instruction so no more need to keep track of a reqRemoveList and clean it up
every tick
first change in an optimization that will stop InOrder from allocating new memory for every instruction's
request to a resource. This gets expensive since every instruction needs to access ~10 requests before
graduation. Instead, the plan is to allocate just enough resource request objects to satisfy each resource's
bandwidth (e.g. the execution unit would need to allocate 3 resource request objects for a 1-issue pipeline
since on any given cycle it could have 2 read requests and 1 write request) and then let the instructions
contend and reuse those allocated requests. The end result is a smaller memory footprint for the InOrder model
and increased simulation performance
Currently the wakeup function for the PerfectSwitch contains three loops -
loop on number of virtual networks
loop on number of incoming links
loop till all messages for this (link, network) have been routed
With an 8 processor mesh network and Hammer protocol, about 11-12% of the
was observed to have been spent in this function, which is the highest
amongst all the functions. It was found that the innermost loop is executed
about 45 times per invocation of the wakeup function, when each invocation
of the wakeup function processes just about one message.
The patch tries to do away with the redundant executions of the innermost
loop. Counters have been added for each virtual network that record the
number of messages that need to be routed for that virtual network. The
inner loops are only executed when the number of messages for that particular
virtual network > 0. This does away with almost 80% of the executions of the
innermost loop. The function now consumes about 5-6% of the total execution
time.
In x86, 32 and 64 bit writes to registers in which registers appear to be 32 or
64 bits wide overwrite all bits of the destination register. This change
removes false dependencies in these cases where the previous value of a
register doesn't need to be read to write a new value. New versions of most
microops are created that have a "Big" suffix which simply overwrite their
destination, and the right version to use is selected during microop
allocation based on the selected data size.
This does not change the performance of the O3 CPU model significantly, I
assume because there are other false dependencies from the condition code bits
in the flags register.
These faults can panic/warn/warn_once, etc., instead of instructions doing
that themselves directly. That way, instructions can be speculatively
executed, and only if they're actually going to commit will their fault be
invoked and the panic, etc., happen.
When redirecting fetch to handle branches, the npc of the current pc state
needs to be left alone. This change makes the pc state record whether or not
the npc already reflects a real value by making it keep track of the current
instruction size, or if no size has been set.
The patch changes the order in which L1 dcache and icache are looked up when
a request comes in. Earlier, if a request came in for instruction fetch, the
dcache was looked up before the icache, to correctly handle self-modifying
code. But, in the common case, dcache is going to report a miss and the
subsequent icache lookup is going to report a hit. Given the invariant -
caches under the same controller keep track of disjoint sets of cache blocks,
we can move the icache lookup before the dcache lookup. In case of a hit in
the icache, using our invariant, we know that the dcache would have reported
a miss. In case of a miss in the icache, we know that icache would have
missed even if the dcache was looked up before looking up the icache.
Effectively, we are doing the same thing as before, though in the common case,
we expect reduction in the number of lookups. This was empirically confirmed
for MOESI hammer. The ratio lookups to access requests is now about 1.1 to 1.
resource skeds are divided into two parts: front end (all insts) and back end (inst. specific)
each of those are implemented as separate lists, so this iterator wraps around
the traditional list iterator so that an instruction can walk it's schedule but seamlessly
transfer from front end to back end when necessary
add a stage scheduler class to replace InstStage in pipeline_traits.cc
use that class to define a default front-end, resource schedule that all
instructions will follow. This will also replace the back end schedule in
pipeline_traits.cc. The reason for adding this is so that we can cache
instruction schedules in the future instead of calling the same function
over/over again as well as constantly dynamically alllocating memory on
every instruction to try to figure out it's schedule
When a table walk is initiated by the fetch stage, the CPU can
potentially move to the idle state and never wake up.
The fetch stage must call cpu->wakeCPU() when a translation completes
(in finishTranslation()).
Uncacheable requests were set as such only in atomic mode.
currState->delayed is checked in place of currState->timing for resetting
currState in atomic mode.
This change fixes an issue where a DTLB fault occurs and redirects fetch to
handle the fault and the ITLB requires a walk which delays translation. In this
case the status of the cpu isn't updated appropriately, and an additional
instruction fetch occurs. Eventually this hits an assert as multiple instruction
fetches are occuring in the system and when the second one returns the
processor is in the wrong state.
Some asserts below are removed because it was always true (typo) and the state
after the initiateAcc() the processor could be in any valid state when a
d-side fault occurs.
Some ISAs (like ARM) relies on hardware page table walkers. For those ISAs,
when a TLB miss occurs, initiateTranslation() can return with NoFault but with
the translation unfinished.
Instructions experiencing a delayed translation due to a hardware page table
walk are deferred until the translation completes and kept into the IQ. In
order to keep track of them, the IQ has been augmented with a queue of the
outstanding delayed memory instructions. When their translation completes,
instructions are re-executed (only their initiateAccess() was already
executed; their DTB translation is now skipped). The IEW stage has been
modified to support such a 2-pass execution.
Setup initial timesync event in initState or loadState so that curTick has
been updated to the new value, otherwise the event is scheduled in the past.
The TBE pointer in the MESI CMP implementation was not being set to NULL
when the TBE is deallocated. This resulted in segmentation fault on testing
the protocol when the ProtocolTrace was switched on.
JMP_FAR_I was unpacking its far pointer operand using sll instead of srl like
it should, and also putting the components in the wrong registers for use by
other microcode.
During iret access LDT/GDT at CPL0 rather than after transition to user mode
(if I'm reading the Intel IA-64 architecture spec correctly, the contents of
the descriptor table are read before the CPL is updated).
The code for Orion 2.0 makes use of printf() at several places where there as
an error in configuration of the model. These have been replaced with fatal().
By stalling and waiting the mandatory queue instead of recycling it, one can
ensure that no incoming messages are starved when the mandatory queue puts
signficant of pressure on the L1 cache controller (i.e. the ruby memtester).
--HG--
rename : src/mem/slicc/ast/WakeUpDependentsStatementAST.py => src/mem/slicc/ast/WakeUpAllDependentsStatementAST.py
The packet now identifies whether static or dynamic data has been allocated and
is used by Ruby to determine whehter to copy the data pointer into the ruby
request. Subsequently, Ruby can be told not to update phys memory when
receiving packets.
Move page table walker state to its own object type, and make the
walker instantiate state for each outstanding walk. By storing the
states in a queue, the walker is able to handle multiple outstanding
timing requests. Note that functional walks use separate state
elements.
In sendSplitData, keep a pointer to the senderState that may be updated after
the call to handle*Packet. This way, if the receiver updates the packet
senderState, it can still be accessed in sendSplitData.
Double packet delete problem is due to an interrupt device deleting a packet that the SimpleTimingPort also deletes. Since MessagePort descends from SimpleTimingPort, simply reimplement the failing code from SimpleTimingPort: recvTiming.
Separate data VCs and ctrl VCs in garnet, as ctrl VCs have 1 buffer per VC,
while data VCs have > 1 buffers per VC. This is for correct power estimations.
Maintain all information about an instruction's fault in the DynInst object rather
than any cpu-request object. Also, if there is a fault during the execution stage
then just save the fault inside the instruction and trap once the instruction
tries to graduate
Give fetch unit it's own parameterizable fetch buffer to read from. Very inefficient
(architecturally and in simulation) to continually fetch at the granularity of the
wordsize. As expected, the number of fetch memory requests drops dramatically
instead of having one cache-unit class be responsible for both data and code
accesses, separate code that is just for fetch in it's own derived class off the
original base class. This makes the code easier to manage as well as handle
future cases of special fetch handling
allow the user to specify how many instructions a pipeline stage can process
on any given cycle (stageWidth...i.e.bandwidth) by setting the parameter through
the python interface rather than compile the code after changing the *.cc file.
(we always had the parameter there, but still used the static 'ThePipeline::StageWidth'
instead)
-
Since StageWidth is now dynamically defined, change the interstage communication
structure to use a vector and get rid of array and array handling index (toNextStageIndex)
since we can just make calls to the list for the same information
use skidbuffer as only location for instructions between stages. before,
we had the insts queue from the prior stage and the skidbuffer for the
current stage, but that gets confusing and this consolidation helps
when handling squash cases
manage insertion and deletion like a queue but will need
access to internal elements for future changes
Currently, skidbuffer manages any instruction that was
in a stage but could not complete processing, however
we will want to manage all blocked instructions (from prev stage
and from cur. stage) in just one buffer.
Previous code was marking CPU activity on almost every cycle due to a bug in
tracking the status of pipeline stages. This disables the CPU from sleeping
on long latency stalls and increases simulation time
This makes sure that the address ranges requested for caches and uncached ports
don't conflict with each other, and that accesses which are always uncached
(message signaled interrupts for instance) don't waste time passing through
caches.
Moving the definition of NoFault into fault.hh doesn't bring any new
dependencies with it, and allows some files to include just fault.hh which has
less baggage. NoFault will still be available to everything that includes
faults.hh because it includes fault.hh.
M5 skips over any simulated time where it doesn't have any work to do. When
the simulation is active, the time skipped is short and the work done at any
point in time is relatively substantial. If the time between events is long
and/or the work to do at each event is small, it's possible for simulated time
to pass faster than real time. When running a benchmark that can be good
because it means the simulation will finish sooner in real time. When
interacting with the real world through, for instance, a serial terminal or
bridge to a real network, this can be a problem. Human or network response time
could be greatly exagerated from the perspective of the simulation and make
simulated events happen "too soon" from an external perspective.
This change adds the capability to force the simulation to run no faster than
real time. It does so by scheduling a periodic event that checks to see if
its simulated period is shorter than its real period. If it is, it stalls the
simulation until they're equal. This is called time syncing.
A future change could add pseudo instructions which turn time syncing on and
off from within the simulation. That would allow time syncing to be used for
the interactive parts of a session but then turned off when running a
benchmark using the m5 utility program inside a script. Time syncing would
probably not happen anyway while running a benchmark because there would be
plenty of work for M5 to do, but the event overhead could be avoided.
Any change of control flow now resets the itstate to 0 mask and 0 condition,
except where the control flow alteration write into the cpsr register. These
case, for example return from an iterrupt, require the predecoder to recover
the itstate.
As there is a window of opportunity between the return from an interrupt
changing the control flow at the head of the pipe and the commit of the update
to the CPSR, the predecoder needs to be able to grab the ITstate early. This
is now handled by setting the forcedItState inside a PCstate for the control
flow altering instruction.
That instruction will have the correct mask/cond, but will not have a valid
itstate until advancePC is called (note this happens to advance the execution).
When the new PCstate is copy constructed it gets the itstate cond/mask, and
upon advancing the PC the itstate becomes valid.
Subsequent advancing invalidates the state and zeroes the cond/mask. This is
handled in isolation for the ARM ISA and should have no impact on other ISAs.
Refer arch/arm/types.hh and arch/arm/predecoder.cc for the details.
Without this change 0 is always used for the youngest sequence number if
a squash occured and the ROB was empty (E.g. an instruction is marked
serializeAfter or a fetch stall prevents other instructions from issuing).
Using 0 there is a race to rename where an instruction that committed the
same cycle as the squashing instruction can have it's renamed state undone
by the squash using sequence number 0.
I'm not positive this is the correct fix, but it's working right now.
Either we need to do something like this, prevent the misc reg from being renamed at all,
or there something else going on. We need to find the root cause as to why
this is only a problem sometimes.
The squash inside the fetch unit should not attempt to remove them from the
branch predictor as non-control instructions are not pushed into the predictor.
When this condition occurs the cpu should restart the fetch stage to fetch from
the original execution path. Fault handling in the commit stage is cleaned up a
little bit so the control flow is simplier. Finally, if an instruction is being
used to carry a fault it isn't executed, so the fault propagates appropriately.
The purpose of this patch is to change the way CacheMemory interfaces with
coherence protocols. Currently, whenever a cache controller (defined in the
protocol under consideration) needs to carry out any operation on a cache
block, it looks up the tag hash map and figures out whether or not the block
exists in the cache. In case it does exist, the operation is carried out
(which requires another lookup). As observed through profiling of different
protocols, multiple such lookups take place for a given cache block. It was
noted that the tag lookup takes anything from 10% to 20% of the simulation
time. In order to reduce this time, this patch is being posted.
I have to acknowledge that the many of the thoughts that went in to this
patch belong to Brad.
Changes to CacheMemory, TBETable and AbstractCacheEntry classes:
1. The lookup function belonging to CacheMemory class now returns a pointer
to a cache block entry, instead of a reference. The pointer is NULL in case
the block being looked up is not present in the cache. Similar change has
been carried out in the lookup function of the TBETable class.
2. Function for setting and getting access permission of a cache block have
been moved from CacheMemory class to AbstractCacheEntry class.
3. The allocate function in CacheMemory class now returns pointer to the
allocated cache entry.
Changes to SLICC:
1. Each action now has implicit variables - cache_entry and tbe. cache_entry,
if != NULL, must point to the cache entry for the address on which the action
is being carried out. Similarly, tbe should also point to the transaction
buffer entry of the address on which the action is being carried out.
2. If a cache entry or a transaction buffer entry is passed on as an
argument to a function, it is presumed that a pointer is being passed on.
3. The cache entry and the tbe pointers received __implicitly__ by the
actions, are passed __explicitly__ to the trigger function.
4. While performing an action, set/unset_cache_entry, set/unset_tbe are to
be used for setting / unsetting cache entry and tbe pointers respectively.
5. is_valid() and is_invalid() has been made available for testing whether
a given pointer 'is not NULL' and 'is NULL' respectively.
6. Local variables are now available, but they are assumed to be pointers
always.
7. It is now possible for an object of the derieved class to make calls to
a function defined in the interface.
8. An OOD token has been introduced in SLICC. It is same as the NULL token
used in C/C++. If you are wondering, OOD stands for Out Of Domain.
9. static_cast can now taken an optional parameter that asks for casting the
given variable to a pointer of the given type.
10. Functions can be annotated with 'return_by_pointer=yes' to return a
pointer.
11. StateMachine has two new variables, EntryType and TBEType. EntryType is
set to the type which inherits from 'AbstractCacheEntry'. There can only be
one such type in the machine. TBEType is set to the type for which 'TBE' is
used as the name.
All the protocols have been modified to conform with the new interface.
This test exercises each of the functions in the reference counting pointer
implementation individually (except get()) and verifies they have some
minimially expected behavior. It also checks that reference counted objects
are freed when their usage count goes to 0 in some basic situations,
specifically a pointer being set to NULL and a pointer being deleted.
There's no reason for it to derive from SimLoopExitEvent.
This whole drain thing needs to be redone eventually,
but this is a stopgap to make later changes to
SimLoopExitEvent feasible.
Avoid direct references to mainEventQueue in pseudo-insts
by indirecting through associated CPU object.
Made exitSimLoop() more flexible to enable some of these.
There were several copies of similar functions that looked
like they all replicated reschedule(), so I replaced them
with direct calls. Keeping this separate from the previous
cset since there may be some subtle functional differences
if the code ever reschedules an event that is scheduled but
not squashed (though none were detected in the regressions).
Events need to be scheduled on the queue assigned
to the SimObject, not on the global queue (which
should be going away).
Also cleaned up a number of redundant expressions
that made the code unnecessarily verbose.
I like the brevity of Ali's recent change, but the ambiguity of
sometimes showing the source and sometimes the target is a little
confusing. This patch makes scons typically list all sources and
all targets for each action, with the common path prefix factored
out for brevity. It's a little more verbose now but also more
informative.
Somehow Ali talked me into adding colors too, which is a whole
'nother story.
This patch changes the manner in which data is copied from L1 to L2 cache in
the implementation of the Hammer's cache coherence protocol. Earlier, data was
copied directly from one cache entry to another. This has been broken in to
two parts. First, the data is copied from the source cache entry to a
transaction buffer entry. Then, data is copied from the transaction buffer
entry to the destination cache entry.
This has been done to maintain the invariant - at any given instant, multiple
caches under a controller are exclusive with respect to each other.
These files really aren't general enough to belong in src/base.
This patch doesn't reorder include lines, leaving them unsorted
in many cases, but Nate's magic script will fix that up shortly.
--HG--
rename : src/base/sched_list.hh => src/cpu/sched_list.hh
rename : src/base/timebuf.hh => src/cpu/timebuf.hh
Ran all the source files through 'perl -pi' with this script:
s|\s*(};?\s*)?/\*\s*(end\s*)?namespace\s*(\S+)\s*\*/(\s*})?|} // namespace $3|;
s|\s*};?\s*//\s*(end\s*)?namespace\s*(\S+)\s*|} // namespace $2\n|;
s|\s*};?\s*//\s*(\S+)\s*namespace\s*|} // namespace $1\n|;
Also did a little manual editing on some of the arch/*/isa_traits.hh files
and src/SConscript.
These operators were expecting a const T& instead of a const T*, and were not
being picked up and used by gcc in the right places as a result. Apparently no
one used these operators before. A unit test which exposed these problems,
verified the solution, and checks other basic functionality is on the way.
Two functions in src/mem/ruby/system/PerfectCacheMemory.hh, tryCacheAccess()
and cacheProbe(), end with calls to panic(). Both of these functions have
return type other than void. Any file that includes this header file fails
to compile because of the missing return statement. This patch adds dummy
values so as to avoid the compiler warnings.
This diff is for changing the way ASSERT is handled in Ruby. m5.fast
compiles out the assert statements by using the macro NDEBUG. Ruby uses the
macro RUBY_NO_ASSERT to do so. This macro has been removed and NDEBUG has
been put in its place.
The store queue doesn't need to be ISA specific and architectures can
frequently store more than an int registers worth of data. A 128 bits seems
more common, but even 256 bits may be appropriate. Pretty much anything less
than a cache line size is buildable.
For SPARC ASIs are added to the ExtMachInst. If the ASI is changed simply
marking the instruction as Serializing isn't enough beacuse that only
stops rename. This provides a mechanism to squash all the instructions
and refetch them
ARM instructions updating cumulative flags (ARM FP exceptions and saturation
flags) are not serialized.
Added aliases for ARM FP exceptions and saturation flags in FPSCR. Removed
write accesses to the FP condition codes for most ARM VFP instructions: only
VCMP and VCMPE instructions update the FP condition codes. Removed a potential
cause of seg. faults in the O3 model for NEON memory macro-ops (ARM).
New parameter forms are:
IP address in the format "a.b.c.d" where a-d are from decimal 0 to 255.
IP address with netmask which is an IP followed by "/n" where n is a netmask
length in bits from decimal 0 to 32 or by "/e.f.g.h" where e-h are from
decimal 0 to 255 and which is all 1 bits followed by all 0 bits when
represented in binary. These can also be specified as an integral IP and
netmask passed in separately.
IP address with port which is an IP followed by ":p" where p is a port index
from decimal 0 to 65535. These can also be specified as an integral IP and
port value passed in separately.
This change makes O3 flatten floating point destination registers, and also
fixes misc register flattening so that it's correctly repositioned relative to
the resized regions for integer and floating point indices.
It also fixes some overly long lines.
In the case of a split transaction and a cache that is faster than a CPU we
could get two responses before next_tick expires. Add an event that is
scheduled in this case and return false rather than asserting.
The L1 cache may have been accessed to provide this data, which confuses
it, if it ends up being accesses twice in one cycle. Instead wait 1 tick
which will force the timing simple CPU to forward to its next clock cycle
when the translation completes.
Also prevent multiple outstanding table walks from occuring at once.
This change modifies the way prefetches work. They are now like normal loads
that don't writeback a register. Previously prefetches were supposed to call
prefetch() on the exection context, so they executed with execute() methods
instead of initiateAcc() completeAcc(). The prefetch() methods for all the CPUs
are blank, meaning that they get executed, but don't actually do anything.
On Alpha dead cache copy code was removed and prefetches are now normal ops.
They count as executed operations, but still don't do anything and IsMemRef is
not longer set on them.
On ARM IsDataPrefetch or IsInstructionPreftech is now set on all prefetch
instructions. The timing simple CPU doesn't try to do anything special for
prefetches now and they execute with the normal memory code path.
The build_dir parameter name has been deprecated and replaced with
variant_dir. This change switches us over to avoid warning spew in newer
versions of scons.
This change is a low level and pervasive reorganization of how PCs are managed
in M5. Back when Alpha was the only ISA, there were only 2 PCs to worry about,
the PC and the NPC, and the lsb of the PC signaled whether or not you were in
PAL mode. As other ISAs were added, we had to add an NNPC, micro PC and next
micropc, x86 and ARM introduced variable length instruction sets, and ARM
started to keep track of mode bits in the PC. Each CPU model handled PCs in
its own custom way that needed to be updated individually to handle the new
dimensions of variability, or, in the case of ARMs mode-bit-in-the-pc hack,
the complexity could be hidden in the ISA at the ISA implementation's expense.
Areas like the branch predictor hadn't been updated to handle branch delay
slots or micropcs, and it turns out that had introduced a significant (10s of
percent) performance bug in SPARC and to a lesser extend MIPS. Rather than
perpetuate the problem by reworking O3 again to handle the PC features needed
by x86, this change was introduced to rework PC handling in a more modular,
transparent, and hopefully efficient way.
PC type:
Rather than having the superset of all possible elements of PC state declared
in each of the CPU models, each ISA defines its own PCState type which has
exactly the elements it needs. A cross product of canned PCState classes are
defined in the new "generic" ISA directory for ISAs with/without delay slots
and microcode. These are either typedef-ed or subclassed by each ISA. To read
or write this structure through a *Context, you use the new pcState() accessor
which reads or writes depending on whether it has an argument. If you just
want the address of the current or next instruction or the current micro PC,
you can get those through read-only accessors on either the PCState type or
the *Contexts. These are instAddr(), nextInstAddr(), and microPC(). Note the
move away from readPC. That name is ambiguous since it's not clear whether or
not it should be the actual address to fetch from, or if it should have extra
bits in it like the PAL mode bit. Each class is free to define its own
functions to get at whatever values it needs however it needs to to be used in
ISA specific code. Eventually Alpha's PAL mode bit could be moved out of the
PC and into a separate field like ARM.
These types can be reset to a particular pc (where npc = pc +
sizeof(MachInst), nnpc = npc + sizeof(MachInst), upc = 0, nupc = 1 as
appropriate), printed, serialized, and compared. There is a branching()
function which encapsulates code in the CPU models that checked if an
instruction branched or not. Exactly what that means in the context of branch
delay slots which can skip an instruction when not taken is ambiguous, and
ideally this function and its uses can be eliminated. PCStates also generally
know how to advance themselves in various ways depending on if they point at
an instruction, a microop, or the last microop of a macroop. More on that
later.
Ideally, accessing all the PCs at once when setting them will improve
performance of M5 even though more data needs to be moved around. This is
because often all the PCs need to be manipulated together, and by getting them
all at once you avoid multiple function calls. Also, the PCs of a particular
thread will have spatial locality in the cache. Previously they were grouped
by element in arrays which spread out accesses.
Advancing the PC:
The PCs were previously managed entirely by the CPU which had to know about PC
semantics, try to figure out which dimension to increment the PC in, what to
set NPC/NNPC, etc. These decisions are best left to the ISA in conjunction
with the PC type itself. Because most of the information about how to
increment the PC (mainly what type of instruction it refers to) is contained
in the instruction object, a new advancePC virtual function was added to the
StaticInst class. Subclasses provide an implementation that moves around the
right element of the PC with a minimal amount of decision making. In ISAs like
Alpha, the instructions always simply assign NPC to PC without having to worry
about micropcs, nnpcs, etc. The added cost of a virtual function call should
be outweighed by not having to figure out as much about what to do with the
PCs and mucking around with the extra elements.
One drawback of making the StaticInsts advance the PC is that you have to
actually have one to advance the PC. This would, superficially, seem to
require decoding an instruction before fetch could advance. This is, as far as
I can tell, realistic. fetch would advance through memory addresses, not PCs,
perhaps predicting new memory addresses using existing ones. More
sophisticated decisions about control flow would be made later on, after the
instruction was decoded, and handed back to fetch. If branching needs to
happen, some amount of decoding needs to happen to see that it's a branch,
what the target is, etc. This could get a little more complicated if that gets
done by the predecoder, but I'm choosing to ignore that for now.
Variable length instructions:
To handle variable length instructions in x86 and ARM, the predecoder now
takes in the current PC by reference to the getExtMachInst function. It can
modify the PC however it needs to (by setting NPC to be the PC + instruction
length, for instance). This could be improved since the CPU doesn't know if
the PC was modified and always has to write it back.
ISA parser:
To support the new API, all PC related operand types were removed from the
parser and replaced with a PCState type. There are two warts on this
implementation. First, as with all the other operand types, the PCState still
has to have a valid operand type even though it doesn't use it. Second, using
syntax like PCS.npc(target) doesn't work for two reasons, this looks like the
syntax for operand type overriding, and the parser can't figure out if you're
reading or writing. Instructions that use the PCS operand (which I've
consistently called it) need to first read it into a local variable,
manipulate it, and then write it back out.
Return address stack:
The return address stack needed a little extra help because, in the presence
of branch delay slots, it has to merge together elements of the return PC and
the call PC. To handle that, a buildRetPC utility function was added. There
are basically only two versions in all the ISAs, but it didn't seem short
enough to put into the generic ISA directory. Also, the branch predictor code
in O3 and InOrder were adjusted so that they always store the PC of the actual
call instruction in the RAS, not the next PC. If the call instruction is a
microop, the next PC refers to the next microop in the same macroop which is
probably not desirable. The buildRetPC function advances the PC intelligently
to the next macroop (in an ISA specific way) so that that case works.
Change in stats:
There were no change in stats except in MIPS and SPARC in the O3 model. MIPS
runs in about 9% fewer ticks. SPARC runs with 30%-50% fewer ticks, which could
likely be improved further by setting call/return instruction flags and taking
advantage of the RAS.
TODO:
Add != operators to the PCState classes, defined trivially to be !(a==b).
Smooth out places where PCs are split apart, passed around, and put back
together later. I think this might happen in SPARC's fault code. Add ISA
specific constructors that allow setting PC elements without calling a bunch
of accessors. Try to eliminate the need for the branching() function. Factor
out Alpha's PAL mode pc bit into a separate flag field, and eliminate places
where it's blindly masked out or tested in the PC.
Code in the CPUs that need a nop to carry a fault can't easily deal with a
microcoded nop. This instruction format provides for one that isn't.
--HG--
rename : src/arch/x86/isa/formats/syscall.isa => src/arch/x86/isa/formats/nop.isa
These flags were being used to identify what alignment a request needed, but
the same information is available using the request size. This change also
eliminates the isMisaligned function. If more complicated alignment checks are
needed, they can be signaled using the ASI_BITS space in the flags vector like
is currently done with ARM.
This change makes the 8250 device return the value it has for the MCR when
read instead of leaving the packet data unmodified/uninitialized. The value
the UART has for the MCR may not be right, but that's a seperate issue that
apparently hasn't caused any problems to date.
In the process make add skipFuction() to handle isa specific function skipping
instead of ifdefs and other ugliness. For almost all ABIs, 64 bit arguments can
only start in even registers. Size is now passed to getArgument() so that 32
bit systems can make decisions about register selection for 64 bit arguments.
The number argument is now passed by reference because getArgument() will need
to change it based on the size of the argument and the current argument number.
For ARM, if the argument number is odd and a 64-bit register is requested the
number must first be incremented to because all 64 bit arguments are passed
in an even argument register. Then the number will be incremented again to
access both halves of the argument.
Move generated enums into internal.params, which gets
imported into object.params, restoring backward
compatibility for scripts that expect to find them there.
If we write back an exclusive copy, we now mark it
as such, so the cache receiving the writeback can
mark its copy as exclusive. This avoids some
unnecessary upgrade requests when a cache later
tries to re-acquire exclusive access to the block.
It's not the right fix for the checkpoint deadlock problem
Brad was having, and creates another bug where the system can
deadlock on restore. Brad can't reproduce the original bug
right now, so we'll wait until it arises again and then try
to fix it the right way then.
This reduces the scope of those includes and makes it less likely for there to
be a dependency loop. This also moves the hashing functions associated with
ExtMachInst objects to be with the ExtMachInst definitions and out of
utility.hh.
This code is no longer needed because of the preceeding change which adds a
StaticInstPtr parameter to the fault's invoke method, obviating the only use
for this pair of functions.
Also move the "Fault" reference counted pointer type into a separate file,
sim/fault.hh. It would be better to name this less similarly to sim/faults.hh
to reduce confusion, but fault.hh matches the name of the type. We could change
Fault to FaultPtr to match other pointer types, and then changing the name of
the file would make more sense.
This is necessary because versions of swig older than 1.3.39 fail to
do the right thing and try to do relative imports for everything (even
with the package= option to %module). Instead of putting params in
the m5.internal.params package, put params in the m5.internal package
and make all param modules start with param_. Same thing for
m5.internal.enums.
Also, stop importing all generated params into m5.objects. They are
not necessary and now with everything using relative imports we wound
up with pollution of the namespace (where builtin-range got overridden).
--HG--
rename : src/python/m5/internal/enums/__init__.py => src/python/m5/internal/enums.py
rename : src/python/m5/internal/params/__init__.py => src/python/m5/internal/params.py
Instead of putting all object files into m5/object/__init__.py, interrogate
the importer to find out what should be imported.
Instead of creating a single file that lists all of the embedded python
modules, use static object construction to put those objects onto a list.
Do something similar for embedded swig (C++) code.
It doesn't appear to be necessary and it is somewhat odd. I'm pretty
sure that the package parameter to %module does whatever this might
have been before. It's necessary in future revisions anyway.
Corrects an oversight in cset f97b62be544f. The fix there only
failed queued SCUpgradeReq packets that encountered an
invalidation, which meant that the upgrade had to reach the L2
cache. To handle pending requests in the L1 we must similarly
fail StoreCondReq packets too.
Allow lower-level caches (e.g., L2 or L3) to pass exclusive
copies to higher levels (e.g., L1). This eliminates a lot
of unnecessary upgrade transactions on read-write sequences
to non-shared data.
Also some cleanup of MSHR coherence handling and multiple
bug fixes.
Don't assert that the response packet is marked as a response
since it won't always be so for functional accesses.
Also cleanup code to refer to functional accesses rather
than "probes" (old terminology), and mention in the
DPRINTF which type of access we're doing.
Without this flag set, page-crossing requests were not split into two mem
request.
Depending on the alignment bit in the SCTLR, misaligned access could
raise a fault. However it seems unnecessary to implement that.
This fault can used to flush the pipe, not including the faulting instruction.
The particular case I needed this was for a self-modifying code. It needed to
drain the store queue and force the following instruction to refetch from
icache. DCCMVAC cp15 mcr instruction is modified to raise this fault.
When decoding a srs instruction, invalid mode encoding returns invalid instruction.
This can happen when garbage instructions are fetched from mispredicted path
Allow some loads that update the base register to use just two micro-ops. three
micro-ops are only used if the destination register matches the offset register
or the PC is the destination regsiter. If the PC is updated it needs to be
the last micro-op otherwise O3 will mispredict.
inUserMode now can take either a threadcontext or a CPSR value directly. If
given a thread context it just extracts the CPSR and calls the other version.
An inPrivelegedMode function was also implemented which just returns the
opposite of inUserMode.
This is to help tidy up arch/x86. These files should not be used external to
the ISA.
--HG--
rename : src/arch/x86/apicregs.hh => src/arch/x86/regs/apic.hh
rename : src/arch/x86/floatregs.hh => src/arch/x86/regs/float.hh
rename : src/arch/x86/intregs.hh => src/arch/x86/regs/int.hh
rename : src/arch/x86/miscregs.hh => src/arch/x86/regs/misc.hh
rename : src/arch/x86/segmentregs.hh => src/arch/x86/regs/segment.hh
This single parameter replaces the collection of bools that set up various
flavors of microops. A flag parameter also allows other flags to be set like
the serialize before/after flags, etc., without having to change the
constructor.
Since miscellaneous registers bypass wakeup logic, force serialization
to resolve data dependencies through them
* * *
ARM: adding non-speculative/serialize flags for instructions change CPSR
THis allows the CPU to handle predicated-false instructions accordingly.
This particular patch makes loads that are predicated-false to be sent
straight to the commit stage directly, not waiting for return of the data
that was never requested since it was predicated-false.
This allows one two different OS requirements for the same ISA to be handled.
Some OSes are compiled for a virtual address and need to be loaded into physical
memory that starts at address 0, while other bare metal tools generate
images that start at address 0.
This was being done in read(), but if readBytes was called directly it
wouldn't happen. Also, instead of setting the memory blob being read to -1
which would (I believe) require using memset with -1 as a parameter, this now
uses bzero. It's hoped that it's more specialized behavior will make it
slightly faster.
bkt size isn't evenly divisible by max-min and it would round down,
it's possible to sample a distribution and have no place to put the sample.
When this case occured the simulator would assert.
This patch allows messages to be stalled in their input buffers and wait
until a corresponding address changes state. In order to make this work,
all in_ports must be ranked in order of dependence and those in_ports that
may unblock an address, must wake up the stalled messages. Alot of this
complexity is handled in slicc and the specification files simply
annotate the in_ports.
--HG--
rename : src/mem/slicc/ast/CheckAllocateStatementAST.py => src/mem/slicc/ast/StallAndWaitStatementAST.py
rename : src/mem/slicc/ast/CheckAllocateStatementAST.py => src/mem/slicc/ast/WakeUpDependentsStatementAST.py
Patch allows each individual message buffer to have different recycle latencies
and allows the overall recycle latency to be specified at the cmd line. The
patch also adds profiling info to make sure no one processor's requests are
recycled too much.
The main purpose for clearing stats in the unserialize process is so
that the profiler can correctly set its start time to the unserialized
value of curTick.
This patch allows one to disable migratory sharing for those cache blocks that
are accessed by atomic requests. While the implementations are different
between the token and hammer protocols, the motivation is the same. For
Alpha, LLSC semantics expect that normal loads do not unlock cache blocks that
have been locked by LL accesses. Therefore, locked blocks should not transfer
write permissions when responding to these load requests. Instead, only they
only transfer read permissions so that the subsequent SC access can possibly
succeed.
Added drain functions to the RTC and 8254 timer so that periodic interrupts
stop when the system is draining. This patch is needed to checkpoint in
timing mode. Otherwise under certain situations, the event queue will never
be completely empty.
This patch fixes several bugs related to previous inconsistent assumptions on
how many tokens the Owner had. Mike Marty should have fixes these bugs years
ago. :)
Previously, the MOESI_hammer protocol calculated the same latency for L1 and
L2 hits. This was because the protocol was written using the old ruby
assumption that L1 hits used the sequencer fast path. Since ruby no longer
uses the fast-path, the protocol delays L2 hits by placing them on the
trigger queue.
The previous slower ruby latencies created a mismatch between the faster M5
cpu models and the much slower ruby memory system. Specifically smp
interrupts were much slower and infrequent, as well as cpus moving in and out
of spin locks. The result was many cpus were idle for large periods of time.
These changes fix the latency mismatch.
This patch adds back to ruby the capability to understand the response time
for messages that hit in different levels of the cache heirarchy.
Specifically add support for the MI_example, MOESI_hammer, and MOESI_CMP_token
protocols.
This patch adds DMA testing to the Memtester and is inherits many changes from
Polina's old tester_dma_extension patch. Since Ruby does not work in atomic
mode, the atomic mode options are removed.
Replace direct call to unserialize() on each SimObject with a pair of
calls for better control over initialization in both ckpt and non-ckpt
cases.
If restoring from a checkpoint, loadState(ckpt) is called on each
SimObject. The default implementation simply calls unserialize() if
there is a corresponding checkpoint section, so we get backward
compatibility for existing objects. However, objects can override
loadState() to get other behaviors, e.g., doing other programmed
initializations after unserialize(), or complaining if no checkpoint
section is found. (Note that the default warning for a missing
checkpoint section is now gone.)
If not restoring from a checkpoint, we call the new initState() method
on each SimObject instead. This provides a hook for state
initializations that are only required when *not* restoring from a
checkpoint.
Given this new framework, do some cleanup of LiveProcess subclasses
and X86System, which were (in some cases) emulating initState()
behavior in startup via a local flag or (in other cases) erroneously
doing initializations in startup() that clobbered state loaded earlier
by unserialize().
The separate restoreCheckpoint() call is gone; just pass
the checkpoint dir as an optional arg to instantiate().
This change is a precursor to some more extensive
reworking of the startup code.
The old code for handling SimObject children was kind of messy,
with children stored both in _values and _children, and
inconsistent and potentially buggy handling of SimObject
vectors. Now children are always stored in _children, and
SimObject vectors are consistently handled using the
SimObjectVector class.
Also, by deferring the parenting of SimObject-valued parameters
until the end (instead of doing it at assignment), we eliminate
the hole where one could assign a vector of SimObjects to a
parameter then append to that vector, with the appended objects
never getting parented properly.
This patch induces small stats changes in tests with data races
due to changes in the object creation & initialization order.
The new code does object vectors in order and so should be more
stable.
Orphan SimObjects (not in the config hierarchy) could get
created implicitly if they have a port connection to a SimObject
that is in the hierarchy. This means that there are objects on
the C++ SimObject list (created via the C++ SimObject
constructor call) that are unknown to Python and will get
skipped if we walk the hierarchy from the Python side (as we are
about to do). This patch detects this situation and prints an
error message.
Also fix the rubytester config script which happened to rely on
this behavior.
Enforce that the Python Root SimObject is instantiated only
once. The C++ Root object already panics if more than one is
created. This change avoids the need to track what the root
object is, since it's available from Root.getInstance() (if it
exists). It's now redundant to have the user pass the root
object to functions like instantiate(), checkpoint(), and
restoreCheckpoint(), so that arg is gone. Users who use
configs/common/Simulate.py should not notice.
Clean up some minor things left over from the default responder
change in rev 9af6fb59752f. Mostly renaming the 'responder_set'
param to 'use_default_range' to actually reflect what it does...
old name wasn't that descriptive in the first place, but now
it really doesn't make sense at all.
Also got rid of the bogus obsolete assignment to 'bus.responder'
which used to be a parameter but now is interpreted as an
implicit child assignment, and which was giving me problems in
the config restructuring to come. (A good argument for not
allowing implicit child assignments, IMO, but that's water under
the bridge, I'm afraid.)
Also moved the Bus constructor to the .cc file since that's
where it should have been all along.
printMemData is only used in DPRINTFs. If those are removed by compiling
m5.fast, that function is unused, gcc generates a warning, that gets turned
into an error, and the build fails. This change surrounds the function
definition with #if TRACING_ON so it only gets compiled in if the DPRINTFs do
to.
When a request is NO_ACCESS (x86 CDA microinstruction), the memory op
doesn't go to the cache, so TimingSimpleCPU::completeDataAccess needs
to handle the case where the current status of the CPU is Running
and not DcacheWaitResponse or DTBWaitResponse
switching between O3 and another CPU, O3's tick event might still be scheduled
in the event queue (as squashed). Therefore, check for a squashed tick event
as well as a non-scheduled event when taking over from another CPU and deal
with it accordingly.
It would be nice if python had a tree class that would do this for real,
but since we don't, we'll just keep a sorted list of keys and update
it on demand.
If the user sets the environment variable M5_OVERRIDE_PY_SOURCE to
True, then imports that would normally find python code compiled into
the executable will instead first check in the absolute location where
the code was found during the build of the executable. This only
works for files in the src (or extras) directories, not automatically
generated files.
This is a developer feature!
This tidbit was pulled from a larger patch for Tim's sake, so
the comment reflects functions that haven't been exported yet.
I hope to commit them soon so it didn't seem worth cleaning up.
m5 doesnt do stats specific to binary and this resource request stat is probably only
useful for people who really know the ins/outs of the model anyway
replace priority queue with vector of lists(1 list per stage) and place inside a class
so that we have more control of when an instruction uses a particular schedule entry
...
also, this is the 1st step toward making the InOrderCPU fully parameterizable. See the
wiki for details on this process
- use InOrderBPred instead of Resource for DPRINTFs
- account for DELAY SLOT in updating RAS and in squashing
- don't let squashed instructions update the predictor
- the BTB needs to use the ASID not the TID to work for multithreaded programs
- add stats for BTB hits
Requires new "SCUpgradeReq" message that marks upgrades
for store conditionals, so downstream caches can fail
these when they run into invalidations.
See http://www.m5sim.org/flyspray/task/197
Only set the dirty bit when we actually write to a block
(not if we thought we might but didn't, as in a failed
SC or CAS). This requires makeing sure the dirty bit
stays set when we get an exclusive (writable) copy
in a cache-to-cache transfer from another owner, which
n turn requires copying the mem-inhibit flag from
timing-mode requests to their associated responses.
One big difference is that PrioHeap puts the smallest element at the
top of the heap, whereas stl puts the largest element on top, so I
changed all comparisons so they did the right thing.
Some usage of PrioHeap was simply changed to a std::vector, using sort
at the right time, other usage had me just use the various heap functions
in the stl.
This was somewhat tricky because the RefCnt API was somewhat odd. The
biggest confusion was that the the RefCnt object's constructor that
took a TYPE& cloned the object. I created an explicit virtual clone()
function for things that took advantage of this version of the
constructor. I was conservative and used clone() when I was in doubt
of whether or not it was necessary. I still think that there are
probably too many instances of clone(), but hopefully not too many.
I converted several instances of const MsgPtr & to a simple MsgPtr.
If the function wants to avoid the overhead of creating another
reference, then it should just use a regular pointer instead of a ref
counting ptr.
There were a couple of instances where refcounted objects were created
on the stack. This seems pretty dangerous since if you ever
accidentally make a reference to that object with a ref counting
pointer, bad things are bound to happen.
Expand the help text on the --remote-gdb-port option so
people know you can use it to disable remote gdb without
reading the source code, and thus don't waste any time
trying to add a separate option to do that.
Clean up some gdb-related cruft I found while looking
for where one would add a gdb disable option, before
I found the comment that told me that I didn't need
to do that.
Spec2k benchmarks seem to run with atomic or timing mode simple
CPUs. Fixed up some constants, handling of 64 bit arguments,
and marked a few more syscalls ignoreFunc.
This will help keep the high level decode together and not have it spread into
the subordinate decode stuff. The ##include lines still need to be on a line
by themselves, though.
There were four bugs in these instructions. First, the loaded value was being
stored into a floating point register as floating point, changing the value as
it was transfered. Second, the meaning of the "up" bit had been reversed.
Third, the statically sized microop array wasn't bit enough for all possible
inputs. It's now dynamically sized and should always be big enough. Fourth,
the offset was stored as an unsigned 8 bit value. Negative offsets would look
like moderately large positive offsets.
These enter and leave thumbEE mode. Currently thumbEE mode behaves exactly the
same as Thumb mode, but at least this will make it -look- like we're enter and
leaving it. The actual behavioral changes will be implemented in future
changes.
This register will always report 0 caches as implemented. It's not clear how
to find out how many there really are when dealing with an arbitrary
hierarchy.
This register controls access to the coprocessors. This doesn't actually
implement it, it allows writes which don't turn anything off. In other words,
it allows the simulated program to ask for what it already has.
This register is supposed to "Clean and invalidate data or unified cache line
by set/way." Since there isn't a good way to do that, we'll just ignore these
and warn about it.
This change moves the writeback of load multiple instructions to the beginning
of the macroop. That way, the MicroLdrRetUop that changes the mode will
necessarily happen later, ensuring the writeback happens in the original mode.
The actual value in the base register if it also shows up in the register list
is undefined, so it's fine if it gets clobbered by one of the loads. For
stores where the base register is the lowest numbered in the register list,
the original value should be written back. That means stores can't write back
at the beginning, but the mode changing problem doesn't affect them so they
can continue to write back at the end.
Instead of panic immediately when these instructions are executed, an
UndefinedInstruction fault is returned. In FS mode (not currently
implemented), this is the fault that should, to my knowledge, be triggered in
these situations and should be handled using the normal architected
mechanisms. In SE mode, the fault causes a panic when it's invoked that gives
the same information as the instruction did. When/if support for speculative
execution of ARM is supported, this will allow a mispeculated and unrecognized
and/or unimplemented instruction from causing a panic. Only once the
instruction is going to be committed will the fault be invoked, triggering the
panic.
Shifting to the right of a signed value when the MSB is one is technically
undefined behavior, even though in my experience it's done the "right thing"
and sign extended the value. This replaces the arithmetic right shift code in
ARM that uses that coincidence with some code that relies on bit math.
This allows the templates to all be available at the same time before any of
the formats, etc. This breaks an artificial circular dependence.
--HG--
rename : src/arch/arm/isa/formats/pred.isa => src/arch/arm/isa/templates/pred.isa
This isn't technically correct since the .w should only be added if there are
32 and 16 bit encodings, but always having it always is better than never
having it.
Further cleanup should probably be done to make this class be non-Ruby
specific and put it in src/base.
There are probably several cases where this class is used, std::bitset
could be used instead.
Suppose the saturating counters of a branch predictor contain n bits. When the
counter is between 0 and (2^(n-1) - 1), boundaries included, the branch is
predicted as not taken. When the counter is between 2^(n-1) and (2^n - 1),
boundaries included, the branch is predicted as taken.
Time from base/time.hh has a name clash with Time from Ruby's
TypeDefines.hh. Eventually Ruby's Time should go away, so instead of
fixing this properly just try to avoid the clash.
When doing an unsigned 64 bit division with a divisor that has its most
significant bit set, the division code would spill a bit off of the end of a
uint64_t trying to shift the dividend into position. This change adds code
that handles that case specially by purposefully letting it spill and then
going ahead assuming there was a 65th one bit.
This causes builds to happen in sorted order rather than in
declaration order. This gets annoying when you make a global change
and then you notice that the files that are being compiled are jumping
around the directory hierarchy.
when insts execute, they mark the time they finish to be used for subsequent isnts
they may need forwarding of data. However, the regdepmap was using the wrong
value to index into the destination operands of the instruction to be forwarded.
Thus, in some cases, we are checking to see if the 3rd destination register
for an instruction is executed at a certain time, when there is only 1 dest. register
valid. Thus, we get a bad, uninitialized time value that will stall forwarding
causing performance loss but still the correct execution.
- Make the initialized flag always available, not just in debug mode.
- Make the Initialized flag actually use several bits so it is very
unlikely that something that's uninitialized accidentally looks
initialized.
- Add an initialized() function that tells you if the current event is
indeed initialized.
- Clear the flags on delete so it can't be accidentally thought of as
initialized.
- Fix getFlags assert statement. "How did this ever work?"
Symbolic names should still be used, but this makes it easier to do
things like:
Event::Priority MyObject_Pri = Event::Default_Pri + 1
Remember that higher numbers are lower priority (should we fix this?)
In addition to obvious changes, this required a slight change to the slicc
grammar to allow types with :: in them. Otherwise slicc barfs on std::string
which we need for the headers that slicc generates.
make sure to only read 1 src reg. for write-hint and any other similar
'store' instruction. Reading the source reg when its not necessary
can cause the simulator to read from uninitialized values
These recordEvent() calls could cause crashes since they
access the req pointer after it's potentially been
deleted during a failed translation call. (Similar
problem to the traceData bug fixed in the previous cset.)
Moving them above the translation call (as was done
recentlyi in cset 8b2b8e5e7d35) avoids the crash
but doesn't work, since at that point we don't know if
the access is uncached or not.
It's not clear why these calls are there, and no one
seems to use them, so we'll just delete them. If they
are needed, they should be moved to somewhere that's
guaranteed to be after the translation completes but
before the request is possibly deleted, e.g., in
finishTranslation().
Accessing traceData (to call setAddress() and/or setData())
after initiating a timing translation was causing crashes,
since a failed translation could delete the traceData
object before returning.
It turns out that there was never a need to access traceData
after initiating the translation, as the traced data was
always available earlier; this ordering was merely
historical. Furthermore, traceData->setAddress() and
traceData->setData() were being called both from the CPU
model and the ISA definition, often redundantly.
This patch standardizes all setAddress and setData calls
for memory instructions to be in the CPU models and not
in the ISA definition. It also moves those calls above
the translation calls to eliminate the crashes.
Previously, the set size was set to 4. This was mostly do to the fact that a
crazy graduate student use to create networks with 256 l2 cache banks. Now it
is far more likely that users will create systems with less than 64 of any
particular controller type. Therefore Ruby should be optimized for a set size
of 1.
On the config end, if a shared L2 is created for the system, it is
parameterized to have n sharers as defined by option.num_cpus. In addition to
making the cache sharing aware so that discriminating tag policies can make use
of context_ids to make decisions, I added an occupancy AverageStat and an occ %
stat to each cache so that you could know which contexts are occupying how much
cache on average, both in terms of blocks and percentage. Note that since
devices have context_id -1, having an array of occ stats that correspond to
each context_id will break here, so in FS mode I add an extra bucket for device
blocks. This bucket is explicitly not added in SE mode in order to not only
avoid ugliness in the stats.txt file, but to avoid broken stats (some formulas
break when a bucket is 0).
Also, make Formulas work on AverageVector. First, Stat::Average (and thus
Stats::AverageVector) was broken when coming out of a checkpoint and on resets,
this fixes that. Formulas also didn't work with AverageVector, but added
support for that.
When implementing timing address translations instead of atomic, I
forgot to preserve the faults that are returned from the read and
write calls. This patch reinstates them.
When each load or store is sent to the LSQ, we check whether it will cross a
cache line boundary and, if so, split it in two. This creates two TLB
translations and two memory requests. Care has to be taken if the first
packet of a split load is sent but the second blocks the cache. Similarly,
for a store, if the first packet cannot be sent, we must store the second
one somewhere to retry later.
This modifies the LSQSenderState class to record both packets in a split
load or store.
Finally, a new const variable, HasUnalignedMemAcc, is added to each ISA
to indicate whether unaligned memory accesses are allowed. This is used
throughout the changed code so that compiler can optimise away code dealing
with split requests for ISAs that don't need them.
This initiates a timing translation and passes the read or write on to the
processor before waiting for it to finish. Once the translation is finished,
the instruction's state is updated via the 'finish' function. A new
DataTranslation class is created to handle this.
The idea is taken from the implementation of timing translations in
TimingSimpleCPU by Gabe Black. This patch also separates out the timing
translations from this CPU and uses the new DataTranslation class.
- on certain retry requests you can get an assertion failure
- fix by allowing the request to literally "Retry" itself
if it wasnt successful before, and then block any requests
through cache port while waiting for the cache to be
made available for access
when threads are switching in/out the CPU, we need to keep
track of special cases like branches. Add appropriate
variables in ThreadState t track this and then use
these variables when updating pc after context switch
this will be used for when a thread comes back from a cache miss, it needs to update the PCs
because the inst might of been a branch or delayslot in which the next PC isnt always
a straight addition
allow a thread to wakeup and be activated after
it has been in suspended state and another
thread is switched out. Need to give
pipeline stages a "activateThread" function
so that can get to their suspended instruction
when the time is right.
give resources their own specific
activity to do for a "suspend" event
instead of defaulting to deactivating the thread for a
suspend thread event. This really matters
for the fetch sequence unit which wants to remove the
thread from fetching while other units want to
ignore a thread suspension. If you deactivate a thread
in a resource then you may lose some of the allotted
bandwidth that the thread is taking up...
update/add in the use of isThreadReady & isThreadSuspended
functions.Check in activateThread what list a thread is
on so it can be managed accordingly.
-Support ability to activate next ready thread after a cache miss
through the activateNextReadyContext/Thread() functions
-To support this a "readyList" of thread ids is added
-After a cache miss, thread will suspend and then call
activitynextreadythread
allow for events to schedule themselves later if desired. this is important
because of cases like where you need to activate a thread only after the previous
thread has been deactivated. The ordering there has to be enforced
add code to recognize memory stalls in resources and the pipeline as well
as squash a thread if there is a stall and we are in the switch on cache miss
model
add buffer for instructions to switch out to in a pipeline stage
can't squash the instruction and remove the pipeline so we kind of need
to 'suspend' an instruction at the stage while the memory stall resolves
for the switch on cache miss model
- loads were happening on same cycle as the address was generated which is slightly
unrealistic. Instead, force address generation to be on separate cycle from load
initiation
- also, mark the stages in a more traditional way (F-D-X-M-W)
This patch includes the necessary regression updates to test the new ruby
configuration system. The patch includes support for multiple ruby protocols
and adds the ruby random tester. The patch removes atomic mode test for
ruby since ruby does not support atomic mode acceses. These tests can be
added back in when ruby supports atomic mode for real.
--HG--
rename : tests/quick/50.memtest/test.py => tests/quick/60.rubytest/test.py
Removed the dummy power function implementations so that Orion can implement
them correctly. Since Orion lacks modular design, this patch simply enables
scons to compile it. There are no python configuration changes in this patch.
Renamed the MESI directory file to be consistent with all other protocols.
--HG--
rename : src/mem/protocol/MESI_CMP_directory-mem.sm => src/mem/protocol/MESI_CMP_directory-dir.sm
Cleaned up the ruby profilers by moving the memory controller profiling code
out of the main profiler object and into a separate object similar to the
current CacheProfiler. Both the CacheProfiler and MemCntrlProfiler are
specific to a particular Ruby object, CacheMemory and MemoryControl
respectively. Therefore, these profilers should not be SimObjects and
created by the python configuration system, but instead private objects. This
simplifies the creation of these profilers.
Reorganized ruby python configuration so that protocol and ruby memory system
configuration code can be shared by multiple front-end configuration files
(i.e. memory tester, full system, and hopefully the regression tester). This
code works for memory tester, but have not tested fs mode.
Modified ruby's tracing support to no longer rely on the RubySystem map
to convert a sequencer string name to a sequencer pointer. As a
temporary solution, the code uses the sim_object find function.
Eventually, we should develop a better fix.
This patch includes a rather substantial change to the memory controller
profiler in order to work with the new configuration system. Most
noteably, the mem_cntrl_profiler no longer uses a string map, but instead
a vector. Eventually this support should be removed from the main
profiler and go into a separate object. Each memory controller should have
a pointer to that new mem_cntrl profile object.
This patch includes the necessary changes to connect ruby objects using
the python configuration system. Mainly it consists of removing
unnecessary ruby object pointers and connecting the necessary object
pointers using the generated param objects. This patch includes the
slicc changes necessary to connect generated ruby objects together using
the python configuraiton system.
The necessary companion conversion of Ruby objects generated by SLICC
are converted to M5 SimObjects in the following patch, so this patch
alone does not compile.
Conversion of Garnet network models is also handled in a separate
patch; that code is temporarily disabled from compiling to allow
testing of interim code.
Though OutPort's message type is not used to generate code, this fix checks
that the programmer's intent is correct. Eventually, we may want to
remove the message type from the OutPort declaration statement.
1) Move alpha-specific code out of page_table.cc:serialize().
2) Begin serializing M5_pid and unserializing it, but adding an function to do optional paramIn so that old checkpoints don't need to be fixed up.
3) Fix up alpha startup code so that the unserialized M5_pid value is properly written to DTB_IPR_ASN.
4) Fix the memory unserialize that I forgot somehow in the last changeset.
5) Add in an agg_se.py to handle aggregated checkpoints. --bench foo-bar plus positional arguments foo bar are the only changes in usage from se.py.
Note this aggregation stuff has only been tested for Alpha and nothing else, though it should take a very minimal amount of work to get it to work with another ISA.
This patch changes the way that Ruby handles atomic RMW instructions. This implementation, unlike the prior one, is protocol independent. It works by locking an address from the sequencer immediately after the read portion of an RMW completes. When that address is locked, the coherence controller will only satisfy requests coming from one port (e.g., the mandatory queue) and will ignore all others. After the write portion completed, the line is unlocked. This should also work with multi-line atomics, as long as the blocks are always acquired in the same order.
In Linux, the set_thread_area system call stores the address of the thread
local storage area into a field of the current thread_info structure. Later,
to access that value, the program uses the rdhwr instruction to read a
"hardware register" with index 29. The 64 bit MIPS manual, volume II, says
that index 29 is reserved for a future ABI extension and should cause a
"Reserved Instruction Exception". In Linux (and potentially other ISAs) that
exception is trapped and emulated to return the value stored by
set_thread_area as if that were actually stored by a physical register.
The tp_value address (as named in the Linux kernel) is ironically stored as a
control register so that it goes with a particular ThreadContext. Syscall
emulation will use that to emulate storing to the OS's thread info structure,
and rdhwr will emulate faulting and returning that value from software by
returning the value itself, as if it was in hardware. In other words, we fake
faking the register in SE mode. In an FS mode implementation it should
work as specified in the manual.
The MIPS ISA object expects to be constructed with a CPU pointer it uses to
look at other thread contexts and allow them to be manipulated with control
registers. Unfortunately, that differs from all the other ISA classes and
would complicate their implementation.
This change makes the event constructor use a CPU pointer pulled out of the
thread context passed to setMiscReg instead.
Added error messages when:
- a state does not exist in a machine's list of known states.
- an event does not exist in a machine
- the actions of a certain machine have not been declared
Connects M5 cpu and dma ports directly to ruby sequencers and dma
sequencers. Rubymem also includes a pio port so that pio requests
and be forwarded to a special pio bus connecting to device pio
ports.
Some of the micro-ops weren't casting 1 to ULL before shifting,
which can cause problems. On the perl makerand input this
caused some values to be negative that shouldn't have been.
The casts are done as ULL(1) instead of 1ULL to match others
in the m5 code base.
The PC indexes in the various register sets was defined in the section for
unaliased registers which was throwing off the indexing. This moves those
where they belong. Also, to make detecting accesses to the PC easier and
because it's in the same place in all modes, the intRegForceUser function
now passes it through as index 15.
Unfortunately my implementation of the movd instruction had two bugs.
In one case, when moving a 32-bit value into an xmm register, the
lower half of the xmm register was not zero extended.
The other case is that xmm was used instead of xmmlm as the source
for a register move. My test case didn't notice this at first
as it moved xmm0 to eax, which both have the same register
number.
This double cast led to rounding errors which caused
some benchmarks to get the wrong values, most notably lucas
which failed spectacularly due to CVTTSD2SI returning an
off-by-one value. equake was also broken.
Specifically, get rid of the big switch statement so more cases can be
handled. Enumerating all the possible settings doesn't scale well. Also do
some minor style clean up.
Add constants for all the modes and registers, maps for aliasing, functions
that use the maps and range check, and use a named constant instead of a magic
number for the microcode register.
This problem is like the one fixed with movhpd a few weeks ago.
A +8 displacement is used to access memory when there should
be none.
This fix is needed for the perlbmk spec2k benchmark to run.
Right now .cc and .hh files are handled separately, but then
they're just munged together at the end by scons, so it
doesn't buy us anything. Might as well munge from the start
since we'll eventually be adding generated Python files
to the list too.
64-bit vsyscall is different than 32-bit.
There are only two syscalls, time and gettimeofday.
On a real system, there is complicated code that implements these
without entering the kernel. That would be complicated to implement in m5.
Instead we just place code that calls the regular syscalls (this is how
tools such as valgrind handle this case).
This is needed for the perlbmk spec2k benchmark.
These are complicated instructions and the micro-code might be suboptimal.
This has been tested with some small sample programs (attached)
The psrldq instruction is needed by various spec2k programs.
This patch implements the movd_Vo_Edp series of instructions.
It addresses various concerns by Gabe Black about which file the
instruction belonged in, as well as supporting REX prefixed
instructions properly.
This instruction is needed for some of the spec2k benchmarks, most
notably bzip2.
This patch implements the haddpd instruction.
It fixes the problem in the previous version (pointed out by Gabe Black)
where an incorrect result would happen if you issue the instruction
with the same argument twice, i.e. "haddpd %xmm0,%xmm0"
This instruction is used by many spec2k benchmarks.
This patch hooks up the truncate, ftruncate, truncate64 and ftruncate64
system calls on 32-bit and 64-bit X86.
These have been tested on both architectures.
ftruncate/ftruncate64 is needed for the f90 spec2k benchmarks.
When accessing arguments for a syscall, the position of an argument depends on
the policies of the ISA, how much space preceding arguments took up, and the
"alignment" of the index for this particular argument into the number of
possible storate locations. This change adjusts getSyscallArg to take its
index parameter by reference instead of value and to adjust it to point to the
possible location of the next argument on the stack, basically just after the
current one. This way, the rules for the new argument can be applied locally
without knowing about other arguments since those have already been taken into
account implicitly.
All system calls have also been changed to reflect the new interface. In a
number of cases this made the implementation clearer since it encourages
arguments to be collected in one place in order and then used as necessary
later, as opposed to scattering them throughout the function or using them in
place in long expressions. It also discourages using getSyscallArg over and
over to retrieve the same value when a temporary would do the job.
This mostly was a matter of changing the license owner to Princeton
which is as it should have been. The code was originally licensed
under the GPL but was relicensed as BSD by Li-Shiuan Peh on July 27,
2009. This relicensing was in an explicit e-mail to Nathan Binkert,
Brad Beckmann, Mark Hill, David Wood, and Steve Reinhardt.
The movdqa instruction should enforce 16-byte alignment.
This implementation does not do that.
These instructions are needed for most of x86_64 spec2k to run.
The st_size entry was in the wrong place
(see linux-2.6.29/arch/x86/include/asm/stat.h )
Also, the packed attribute is needed when compiling on a
64-bit machine, otherwise gcc adds extra padding that
break the layout of the structure.
This adds support for the 32-bit, big endian Power ISA. This supports both
integer and floating point instructions based on the Power ISA Book I v2.06.
Glibc often assumes that memory it receives from the kernel after a brk
system call will contain only zeros. This is important during a calloc,
because it won't clear the new memory itself. In the simulator, if the
new page exists, it will be cleared using this patch, to mimic the kernel's
functionality.
I've tested these on x86 and they work as expected.
In theory for 32-bit x86 we should have some sort of special
handling for the legacy 16-bit uid/gid syscalls, but in practice
modern toolchains don't use the 16-bit versions, and m5 sets the uid
and gid values to be less than 16-bits anyway.
This fix is needed for the perl spec2k benchmarks to run.
When enabled, faulting instructions appear in the trace twice
(once when they fault and again when they're re-executed).
This flag is set by the Exec compound flag for backwards compatibility.
This prevents redundant prefetches from being issued, solving the
occasional 'needsExclusive && !blk->isWritable()' assertion failure
in cache_impl.hh that several people have run into.
Eliminates "prefetch_cache_check_push" flag, neither setting of
which really solved the problem.
This is simply a translation of the C++ slicc into python with very minimal
reorganization of the code. The output can be verified as nearly identical
by doing a "diff -wBur".
Slicc can easily be run manually by using util/slicc
Get rid of misc.py and just stick misc things in __init__.py
Move utility functions out of SCons files and into m5.util
Move utility type stuff from m5/__init__.py to m5/util/__init__.py
Remove buildEnv from m5 and allow access only from m5.defines
Rename AddToPath to addToPath while we're moving it to m5.util
Rename read_command to readCommand while we're moving it
Rename compare_versions to compareVersions while we're moving it.
--HG--
rename : src/python/m5/convert.py => src/python/m5/util/convert.py
rename : src/python/m5/smartdict.py => src/python/m5/util/smartdict.py
The manuals from both AMD and Intel say that when writing to a 32 bit
destination in 64 bit mode, the upper 32 bits of the register are filled with
zeros. They also both say that the CMOV instructions leave their destination
alone when their condition fails. Unfortunately, it seems that CMOV will zero
extend its destination register whether or not it was supposed to actually do
a move on both platforms. This seems to be the only case where this happens,
but it would be hard to say for sure.
This is my best guess as far as what these should do. Other existing microops
use implicit registers, mul1s and mul1u for instance, so this should be ok.
The microop that loads the implicit DoubleBits register would fall into one
of the microop slots for moving to/from special registers.
Register values will be "picked" which will assure they don't have junk beyond
the part we're using. Immediate values don't go through a similar process, so
we should truncate them explicitly.
This changeset contains a lot of different changes that are too
mingled to separate. They are:
1. Added MOESI_CMP_directory
I made the changes necessary to bring back MOESI_CMP_directory,
including adding a DMA controller. I got rid of MOESI_CMP_directory_m
and made MOESI_CMP_directory use a memory controller. Added a new
configuration for two level protocols in general, and
MOESI_CMP_directory in particular.
2. DMA Sequencer uses a generic SequencerMsg
I will eventually make the cache Sequencer use this type as well. It
doesn't contain an offset field, just a physical address and a length.
MI_example has been updated to deal with this.
3. Parameterized Controllers
SLICC controllers can now take custom parameters to use for mapping,
latencies, etc. Currently, only int parameters are supported.
The inconsistency was causing a subtle bug with some of the
constructors where the params had the same name as the fields.
This is also a first step to switching the accessors over to
our new "standard", e.g., getVaddr() -> vaddr().
If the control flow of M5's executable and statetrace's target process get out
of sync even a little, there will be a LOT of output, very little of which
will be useful. There's also almost no hope for recovery. In those cases, we
might as well give up and not generate a huge, mostly worthless trace file.
When registers have incorrect values but aren't actively changing, it's likely
they're not being modified at all. The fact that they're still wrong isn't
very important.
Caches are now responsible for their own statistic gathering. This
requires a direct callback from the protocol on misses, and so all
future protocols need to take this into account.
The DMASequencer was still using a parameter from the old RubyConfig,
causing an offset error when the requested data wasn't block aligned.
This changeset also includes a fix to MI_example for a similar bug.
2. Reintroduced RMW_Read and RMW_Write
3. Defined -2 in the Sequencer as well as made a note about mandatory queue
Did not address the issues in the slicc because remaking the atomics altogether to allow
multiple processors to issue atomic requests at once
This also includes a change to the default Ruby random seed, which was
previously set using the wall clock. It is now set to 1234 so that
the stat files don't change for the regression tester.
Using a look up table changed the run time of the SPARC_FS solaris boot
regression from:
real 14m45.951s
user 13m57.528s
sys 0m3.452s
to:
real 12m19.777s
user 12m2.685s
sys 0m2.420s
This was done with an automated process, so there could be things that were
done in this tree in the past that didn't make it. One known regression
is that atomic memory operations do not seem to work properly anymore.
Inorder expects eaComp to be visible through StaticInst object. This mirrors a similar change
to ALPHA... Needs to be done for SPARC and whatever other ISAs want to use InOrderCPU
TLBUnit no longer used and we also get rid of memAccSize and memAccFlags functions added to ISA and StaticInst
since TLB is not a separate resource to acquire. Instead, TLB access is done before any read/write to memory
and the result is checked before it's sent out to memory.
* * *
inorder was incorrectly storing FP values and confusing the integer/fp storage view of floating point operations. A big issue was knowing trying to infer when were doing single or double precision access
because this lets you know the size of value to store (32-64 bits). This isnt exactly straightforward since alpha uses all 64-bit regs while mips/sparc uses a dual-reg view. by getting this value from
the actual floating point register file, the model can figure out what it needs to store
Remove subinstructions eaComp/memAcc since unused in CPU Models. Instead, create eaComp that is visible from StaticInst object. Gives InOrder model capability of generating address without actually initiating access
* * *
Changes so that InOrder can work for a non-delay-slot ISA like Alpha. Typically, changes have to do with handling misspeculated branches at different points in pipeline
Edit AlphaISA to support the inorder model. Mostly alternate constructor functions and also a few skeleton multithreaded support functions
* * *
Remove namespace from header file. Causes compiler issues that are hard to find
* * *
Separate the TLB from the CPU and allow it to live in the TLBUnit resource. Give CPU accessor functions for access and also bind at construction time
* * *
Expose memory access size and flags through instruction object
(temporarily memAccSize and memFlags to get TLB stuff working.)
This changeset also includes a lot of work from Derek Hower <drh5@cs.wisc.edu>
RubyMemory is now both a driver for Ruby and a port for M5. Changed
makeRequest/hitCallback interface. Brought packets (superficially)
into the sequencer. Modified tester infrastructure to be packet based.
and Ruby can be used together through the example ruby_se.py
script. SPARC parallel applications work, and the timing *seems* right
from combined M5/Ruby debug traces. To run,
% build/ALPHA_SE/m5.debug configs/example/ruby_se.py -c
tests/test-progs/hello/bin/alpha/linux/hello -n 4 -t
1. removed checks from tester files
2. removed else clause in Sequencer and DirectoryMemory else clause is
needed by the tester, it is up to Derek to revive it elsewhere when he
gets to it
Also:
1. Changed m_entries in DirectoryMemory to a map
2. And replaced SIMICS_read_physical_memory with a call to now-dummy
Derek's-to-be readPhysMem function
Add the PROTOCOL sticky option sets the coherence protocol that slicc
will parse and therefore ruby will use. This whole process was made
difficult by the fact that the set of files that are output by slicc
are not easily known ahead of time. The easiest thing wound up being
to write a parser for slicc that would tell me. Incidentally this
means we now have a slicc grammar written in python.
This basically means changing all #include statements and changing
autogenerated code so that it generates the correct paths. Because
slicc generates #includes, I had to hard code the include paths to
mem/protocol.
1) Removing files from the ruby build left some unresovled
symbols. Those have been fixed.
2) Most of the dependencies on Simics data types and the simics
interface files have been removed.
3) Almost all mention of opal is gone.
4) Huge chunks of LogTM are now gone.
5) Handling 1-4 left ~hundreds of unresolved references, which were
fixed, yielding a snowball effect (and the massive size of this
delta).
I did the macro cleanup because I was worried that the SCons scanner
would get confused. This code will hopefully go away soon anyway.
--HG--
rename : src/mem/ruby/config/config.include => src/mem/ruby/config/config.hh
this was double scheduling itself (once in constructor and once in cpu code). also add support for stopping / starting
progress events through repeatEvent flag and also changing the interval of the progress event as well
Start by turning all of the *Source functions into classes
so we can do more calculations and more easily collect the data we need.
Add parameters to the new classes for indicating what sorts of flags the
objects should be compiled with so we can allow certain files to be compiled
without Werror for example.
Lowest priority interrupts are now delivered based on a rotating offset into
the list of potential recipients. There could be parasitic cases were a
processor gets picked on and ends up at that rotating offset all the time, but
it's much more likely that the group will stay consistent and the pain will be
distributed evenly.
This is a hack so that the IO APIC can figure out information about the local
APICs. The local APICs still have no way to find out about each other.
Ideally, when the local APICs update state that's relevant to somebody else,
they'd send an update to everyone. Without being able to do a broadcast, that
would still require knowing who else there is to notify. Other broadcasts are
implemented using assumptions that may not always be true.
The ID as exposed to software can be changed. Tracking those changes in M5
would be cumbersome, especially since there's no guarantee the IDs will remain
unique.
Previously there was one per bus, which caused some coherence problems
when more than one decided to respond. Now there is just one on
the main memory bus. The default bus responder on all other buses
is now the downstream cache's cpu_side port. Caches no longer need
to do address range filtering; instead, we just have a simple flag
to prevent snoops from propagating to the I/O bus.
This patch adds limited multithreading support in syscall-emulation
mode, by using the clone system call. The clone system call works
for Alpha, SPARC and x86, and multithreaded applications run
correctly in Alpha and SPARC.
This frees up needed space for more public flags. Also:
- remove unused Request accessor methods
- make Packet use public Request accessors, so it need not be a friend
This microop does a store and unlocks the requested address. The RISC86
microop ISA doesn't seem to have an equivalent to this, so I'm guessing that
the store following an ldstl is automatically unlocking. We don't do it this
way for performance reasons since the behavior is the same.
For some reason o3 FS init() only called initCPU if the thread state
was Suspended, which was no longer the case. There's no apparent
reason to check, so I whacked the test completely rather than
changing the check to Halted.
The inorder init() was also updated to be symmetric, though the
previous code was just a fancy no-op.
This situation can arise now on the first fetch cycle after
the last active thread is halted. It seems easy enough to
deal with when it happens rather than trying to avoid it.
This provides a common initial status for all threads independent
of CPU model (unlike the prior situation where CPUs initialized
threads to inconsistent states).
This mostly matters for SE mode; in FS mode, ISA-specific startupCPU()
methods generally handle boot-time initialization of thread contexts
(since the right thing to do is ISA-dependent).
Basically merge it in with Halted.
Also had to get rid of a few other functions that
called ThreadContext::deallocate(), including:
- InOrderCPU's setThreadRescheduleCondition.
- ThreadContext::exit(). This function was there to avoid terminating
simulation when one thread out of a multi-thread workload exits, but we
need to find a better (non-cpu-centric) way.
Enable more or less takes the place of check, but also allows stats to
do some other configuration. Prepare moves all of the code that readies
a stat for dumping into a separate function in preparation for supporting
serialization of certain pieces of statistics data.
While we're at it, clean up the visitor code and some of the python code.
This basically works by taking advantage of the curiously recurring template
pattern in an intelligent way so as to reduce the number of lines of code
and hopefully make things a little bit clearer.
This provides an easy way to provide the callbacks into the data side
of things from the info side of things. Rename Wrap to DataWrap so it
is more easily distinguishable from InfoWrap
Fix a few instances where the register form of zext was used where zexti was
intended. Also get rid of the 64 bit only rip relative addressed version since
64 bit and real mode are mutually exclusive.
Basically, this means renaming several things called data to info, which
is information about the statistics. Things that are named data now are
actual data stored for the statistic.
This is mainly to allow the unit test to run without requiring the standard
M5 stats from being initialized (e.g. sim_seconds, sim_ticks, host_seconds)
We previously used the actual wall time for the base timestamps,
making etherdumps non-deterministic. This fixes that problem and
gets rid of the "malformed packet" at the front that we needed to
provide the right base timestamp to wireshark/tcpdump.
Apparently we broke it with the cache rewrite and never noticed.
Thanks to Bao Yungang <baoyungang@gmail.com> for a significant part
of these changes (and for inspiring me to work on the rest).
Some other overdue cleanup on the prefetch code too.
This model currently only works in MIPS_SE mode, so it will take some effort
to clean it up and make it generally useful. Hopefully people are willing to
help make that happen!
This allows me to clean things up so we are up to date with respect to
deprecated features. There are many features scheduled for permanent failure
in scons 2.0 and 0.98.1 provides the most compatability for that. It
also paves the way for some nice new features that I will add soon
