Commit graph

736 commits

Author SHA1 Message Date
Andreas Hansson
337774e192 config: Update memtest to stress test clean writebacks
This patch adds yet another twist to the memtest cache hierarchy, in that
the writeback_clean option is toggled at every level to match the
clusivity of the downstream cache.
2015-11-06 03:26:44 -05:00
Andreas Hansson
7433d77fcf mem: Add an option to perform clean writebacks from caches
This patch adds the necessary commands and cache functionality to
allow clean writebacks. This functionality is crucial, especially when
having exclusive (victim) caches. For example, if read-only L1
instruction caches are not sending clean writebacks, there will never
be any spills from the L1 to the L2. At the moment the cache model
defaults to not sending clean writebacks, and this should possibly be
re-evaluated.

The implementation of clean writebacks relies on a new packet command
WritebackClean, which acts much like a Writeback (renamed
WritebackDirty), and also much like a CleanEvict. On eviction of a
clean block the cache either sends a clean evict, or a clean
writeback, and if any copies are still cached upstream the clean
evict/writeback is dropped. Similarly, if a clean evict/writeback
reaches a cache where there are outstanding MSHRs for the block, the
packet is dropped. In the typical case though, the clean writeback
allocates a block in the downstream cache, and marks it writable if
the evicted block was writable.

The patch changes the O3_ARM_v7a L1 cache configuration and the
default L1 caches in config/common/Caches.py
2015-11-06 03:26:43 -05:00
Andreas Hansson
afa252b0b9 config: Update memtest to stress test cache clusivity
This patch adds an new twist to the memtest cache hierarchy, in that
it switches from mostly inclusive to mostly exclusive at every level
in the tree. This has helped weed out plenty issues, and serves as a
good stress tests.
2015-11-06 03:26:42 -05:00
Andreas Hansson
654266f39c mem: Add cache clusivity
This patch adds a parameter to control the cache clusivity, that is if
the cache is mostly inclusive or exclusive. At the moment there is no
intention to support strict policies, and thus the options are: 1)
mostly inclusive, or 2) mostly exclusive.

The choice of policy guides the behaviuor on a cache fill, and a new
helper function, allocOnFill, is created to encapsulate the decision
making process. For the timing mode, the decision is annotated on the
MSHR on sending out the downstream packet, and in atomic we directly
pass the decision to handleFill. We (ab)use the tempBlock in cases
where we are not allocating on fill, leaving the rest of the cache
unaffected. Simple and effective.

This patch also makes it more explicit that multiple caches are
allowed to consider a block writable (this is the case
also before this patch). That is, for a mostly inclusive cache,
multiple caches upstream may also consider the block exclusive. The
caches considering the block writable/exclusive all appear along the
same path to memory, and from a coherency protocol point of view it
works due to the fact that we always snoop upwards in zero time before
querying any downstream cache.

Note that this patch does not introduce clean writebacks. Thus, for
clean lines we are essentially removing a cache level if it is made
mostly exclusive. For example, lines from the read-only L1 instruction
cache or table-walker cache are always clean, and simply get dropped
rather than being passed to the L2. If the L2 is mostly exclusive and
does not allocate on fill it will thus never hold the line. A follow
on patch adds the clean writebacks.

The patch changes the L2 of the O3_ARM_v7a CPU configuration to be
mostly exclusive (and stats are affected accordingly).
2015-11-06 03:26:41 -05:00
Nilay Vaish
6433a10749 configs: fix bug introduced due to 276ad9121192
I had made a typo in changeset 276ad9121192.  This changeset fixes it
2015-11-04 12:36:28 -06:00
Erfan Azarkhish
100cbc9cf6 mem: hmc: top level design
This patch enables modeling a complete Hybrid Memory Cube (HMC) device. It
highly reuses the existing components in gem5's general memory system with some
small modifications. This changeset requires additional patches to model a
complete HMC device.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-11-03 12:17:56 -06:00
Palle Lyckegaard
2cb491379b sparc: add missing parameter to makeSparcSystem()
makeSparcSystem() in configs/common/FSConfig.py is missing the cmdLine
parameter Without the parameter the simulation fails to start.  With the
parameter the simulation starts properly.
2015-11-03 12:17:55 -06:00
Nilay Vaish
4453537ead ruby: profiler: provide the number of vnets through ruby system
The aim is to ultimately do away with the static function
Network::getNumberOfVirtualNetworks().
2015-10-14 00:29:43 -05:00
Andreas Hansson
7dd171ba96 config: Fix 'learning gem5' configs after SMT push
This patch updates the 'learning gem5' example scripts to match the
recent push of the SMT patches.
2015-10-01 04:07:15 -04:00
Mitch Hayenga
a5c4eb3de9 isa,cpu: Add support for FS SMT Interrupts
Adds per-thread interrupt controllers and thread/context logic
so that interrupts properly get routed in SMT systems.
2015-09-30 11:14:19 -05:00
Mitch Hayenga
582a0148b4 config,cpu: Add SMT support to Atomic and Timing CPUs
Adds SMT support to the "simple" CPU models so that they can be
used with other SMT-supported CPUs. Example usage: this enables
the TimingSimpleCPU to be used to warmup caches before swapping to
detailed mode with the in-order or out-of-order based CPU models.
2015-09-30 11:14:19 -05:00
Andreas Hansson
40fcb59c54 util: Fix minor issues in DRAM sweep scripts
This patch fixes a few issues in the sweep scripts, bringing them
up-to-date with the latest memory configs and options.
2015-09-25 06:45:50 -04:00
Jason Lowe-Power
f065f9941b config: Add configs scripts used in Learning gem5
Added a new directory in configs (learning_gem5) to hold the scripts that are
used in the book. See http://lowepower.com/jason/learning_gem5/ for a working
copy. For now, only the scripts in Part 1: Getting started with gem5
have been added. A separate patch adds tests for these scripts.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-09-16 09:35:36 -05:00
Nilay Vaish
bc5be9ac43 config: allow ruby to be used with Minor CPU 2015-09-06 23:11:11 -05:00
Nilay Vaish
fe47f0a72f ruby: remove random seed
We no longer use the C library based random number generator: random().
Instead we use the C++ library provided rng.  So setting the random seed for
the RubySystem class has no effect.  Hence the variable and the corresponding
option are being dropped.
2015-09-01 15:50:33 -05:00
Nilay Vaish
a60a93eb05 ruby: specify number of vnets for each protocol
The default value for number of virtual networks is being removed.  Each protocol
should now specify the value it needs.
2015-08-30 12:24:18 -05:00
Andreas Hansson
ddfa96cf45 mem: Add explicit Cache subclass and make BaseCache abstract
Open up for other subclasses to BaseCache and transition to using the
explicit Cache subclass.

--HG--
rename : src/mem/cache/BaseCache.py => src/mem/cache/Cache.py
2015-08-21 07:03:23 -04:00
Andreas Hansson
d71a0d790d ruby: Move Rubys cache class from Cache.py to RubyCache.py
This patch serves to avoid name clashes with the classic cache. For
some reason having two 'SimObject' files with the same name creates
problems.

--HG--
rename : src/mem/ruby/structures/Cache.py => src/mem/ruby/structures/RubyCache.py
2015-08-21 07:03:21 -04:00
Nilay Vaish
2f44dada68 ruby: reverts to changeset: bf82f1f7b040 2015-08-19 10:02:01 -05:00
Nilay Vaish
d0cf41300b ruby: profiler: provide the number of vnets through ruby system
The aim is to ultimately do away with the static function
Network::getNumberOfVirtualNetworks().
2015-08-14 19:28:44 -05:00
Nilay Vaish
d660b3145b ruby: remove random seed
We no longer use the C library based random number generator: random().
Instead we use the C++ library provided rng.  So setting the random seed for
the RubySystem class has no effect.  Hence the variable and the corresponding
option are being dropped.
2015-08-14 19:28:44 -05:00
Joel Hestness
905c0b347c ruby: Protocol changes for SimObject MessageBuffers 2015-08-14 00:19:45 -05:00
Joel Hestness
581bae9ecb ruby: Expose MessageBuffers as SimObjects
Expose MessageBuffers from SLICC controllers as SimObjects that can be
manipulated in Python. This patch has numerous benefits:
1) First and foremost, it exposes MessageBuffers as SimObjects that can be
manipulated in Python code. This allows parameters to be set and checked in
Python code to avoid obfuscating parameters within protocol files. Further, now
as SimObjects, MessageBuffer parameters are printed to config output files as a
way to track parameters across simulations (e.g. buffer sizes)

2) Cleans up special-case code for responseFromMemory buffers, and aligns their
instantiation and use with mandatoryQueue buffers. These two special buffers
are the only MessageBuffers that are exposed to components outside of SLICC
controllers, and they're both slave ends of these buffers. They should be
exposed outside of SLICC in the same way, and this patch does it.

3) Distinguishes buffer-specific parameters from buffer-to-network parameters.
Specifically, buffer size, randomization, ordering, recycle latency, and ports
are all specific to a MessageBuffer, while the virtual network ID and type are
intrinsics of how the buffer is connected to network ports. The former are
specified in the Python object, while the latter are specified in the
controller *.sm files. Unlike buffer-specific parameters, which may need to
change depending on the simulated system structure, buffer-to-network
parameters can be specified statically for most or all different simulated
systems.
2015-08-14 00:19:44 -05:00
Joel Hestness
9567c839fe ruby: Remove the RubyCache/CacheMemory latency
The RubyCache (CacheMemory) latency parameter is only used for top-level caches
instantiated for Ruby coherence protocols. However, the top-level cache hit
latency is assessed by the Sequencer as accesses flow through to the cache
hierarchy. Further, protocol state machines should be enforcing these cache hit
latencies, but RubyCaches do not expose their latency to any existng state
machines through the SLICC/C++ interface. Thus, the RubyCache latency parameter
is superfluous for all caches. This is confusing for users.

As a step toward pushing L0/L1 cache hit latency into the top-level cache
controllers, move their latencies out of the RubyCache declarations and over to
their Sequencers. Eventually, these Sequencer parameters should be exposed as
parameters to the top-level cache controllers, which should assess the latency.
NOTE: Assessing these latencies in the cache controllers will require modifying
each to eliminate instantaneous Ruby hit callbacks in transitions that finish
accesses, which is likely a large undertaking.
2015-08-14 00:19:37 -05:00
Matthias Jung
8723b08dbf misc: Coupling gem5 with SystemC TLM2.0
Transaction Level Modeling (TLM2.0) is widely used in industry for creating
virtual platforms (IEEE 1666 SystemC). This patch contains a standard compliant
implementation of an external gem5 port, that enables the usage of gem5 as a
TLM initiator component in SystemC based virtual platforms. Both TLM coding
paradigms loosely timed (b_transport) and aproximately timed (nb_transport) are
supported.

Compared to the original patch a TLM memory manager was added. Furthermore, the
transaction object was removed and for each TLM payload a PacketPointer that
points to the original gem5 packet is added as an TLM extension.  For event
handling single events are now created.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-08-03 23:08:40 -05:00
Nilay Vaish
3d782f8df7 ruby: correctly number the sequencer in MESI_Three_Level.py 2015-08-03 22:44:27 -05:00
David Hashe
fbb220b4ae config: add base class for ruby controllers
The CntrlBase python class handles configuration parameters such as running
counts of controllers and sequencers.
2015-07-20 09:15:18 -05:00
David Hashe
1850ed410f ruby: initialize replacement policies with their own simobjs
this is in preparation for other replacement policies that take additional
parameters.
2015-07-20 09:15:18 -05:00
Nilay Vaish
0b163ea707 configs: network test: remove redundant physical memory 2015-07-21 10:08:25 -05:00
Brandon Potter
9eda4bdc5a ruby: remove extra whitespace and correct misspelled words 2015-07-10 16:05:23 -05:00
David Hashe
64af6dafb1 config: Update location of ruby topologies in help
Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-07-04 10:43:47 -05:00
Andreas Hansson
b93c912013 mem: Remove redundant is_top_level cache parameter
This patch takes the final step in removing the is_top_level parameter
from the cache. With the recent changes to read requests and write
invalidations, the parameter is no longer needed, and consequently
removed.

This also means that asymmetric cache hierarchies are now fully
supported (and we are actually using them already with L1 caches, but
no table-walker caches, connected to a shared L2).
2015-07-03 10:14:43 -04:00
Andreas Hansson
893533a126 mem: Allow read-only caches and check compliance
This patch adds a parameter to the BaseCache to enable a read-only
cache, for example for the instruction cache, or table-walker cache
(not for x86). A number of checks are put in place in the code to
ensure a read-only cache does not end up with dirty data.

A follow-on patch adds suitable read requests to allow a read-only
cache to explicitly ask for clean data.
2015-07-03 10:14:39 -04:00
Andreas Sandberg
7c4eb3b4d8 kvm, arm: Add support for aarch64
This changeset adds support for aarch64 in kvm. The CPU module
supports both checkpointing and online CPU model switching as long as
no devices are simulated by the host kernel. It currently has the
following limitations:

   * The system register based generic timer can only be simulated by
     the host kernel. Workaround: Use a memory mapped timer instead to
     simulate the timer in gem5.

   * Simulating devices (e.g., the generic timer) in the host kernel
     requires that the host kernel also simulates the GIC.

   * ID registers in the host and in gem5 must match for switching
     between simulated CPUs and KVM. This is particularly important
     for ID registers describing memory system capabilities (e.g.,
     ASID size, physical address size).

   * Switching between a virtualized CPU and a simulated CPU is
     currently not supported if in-kernel device emulation is
     used. This could be worked around by adding support for switching
     to the gem5 (e.g., the KvmGic) side of the device models. A
     simpler workaround is to avoid in-kernel device models
     altogether.
2015-06-01 19:44:19 +01:00
Andreas Hansson
a45c9508ea config: Use null memory for DRAM sweep script
Do not waste time when we do not care about the data.
2015-05-15 13:38:46 -04:00
Wendy Elsasser
20978ee697 config: Add new MemConfig options to DRAM sweep script
Update script to match current MemConfig options with
external_memory_system option set to 0.
2015-05-15 13:38:45 -04:00
Andreas Hansson
554ddc7c07 arch, cpu: Do not forward snoops to table walker
This patch simplifies the overall CPU by changing the TLB caches such
that they do not forward snoops to the table walker port(s). Note that
only ARM and X86 are affected.

There is no reason for the ports to snoop as they do not actually take
any action, and from a performance point of view we are better of not
snooping more than we have to.

Should it at a later point be required to snoop for a particular TLB
design it is easy enough to add it back.
2015-05-05 03:22:27 -04:00
Nilay Vaish
4333549575 cpu: o3: replace issueLatency with bool pipelined
Currently, each op class has a parameter issueLat that denotes the cycles after
which another op of the same class can be issued.  As of now, this latency can
either be one cycle (fully pipelined) or same as execution latency of the op
(not at all pipelined).  The fact that issueLat is a parameter of type Cycles
makes one believe that it can be set to any value.  To avoid the confusion, the
parameter is being renamed as 'pipelined' with type boolean.  If set to true,
the op would execute in a fully pipelined fashion. Otherwise, it would execute
in an unpipelined fashion.
2015-04-29 22:35:22 -05:00
bpotter
936768c8f4 config: enable setting SE-mode environment variables from file 2015-04-23 13:40:18 -07:00
Andreas Hansson
076ea249ae config: Remove memory aliases and rely on class name
Instead of maintaining two lists, rely entirely on the class
name. There is really no point in causing unecessary confusion.
2015-04-20 12:46:29 -04:00
Malek Musleh
826f69b470 config, cpu: fix progress interval for switched CPUs
This patch ensures that the CPU progress Event is triggered for the new set of
switched_cpus that get scheduled (e.g. during fast-forwarding). it also avoids
printing the interval state if the cpu is currently switched out.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-04-14 11:01:10 -05:00
Dibakar Gope
34ad1123ee cpu: re-organizes the branch predictor structure.
Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-04-13 17:33:57 -05:00
Curtis Dunham
c3268f8820 config: Support full-system with SST's memory system
This patch adds an example configuration in ext/sst/tests/ that allows
an SST/gem5 instance to simulate a 4-core AArch64 system with SST's
memHierarchy components providing all the caches and memories.
2015-04-08 15:56:06 -05:00
Andreas Hansson
aeffde5ed5 arm, configs: Do not forward snoops from I cache
This fix simply tells the I cache to not forward snoops to the fetch
unit (since there is really no reason to do so).
2015-03-27 04:56:10 -04:00
Steve Reinhardt
c55749d998 config: expand '~' and '~user' in paths 2015-03-23 16:14:19 -07:00
Curtis Dunham
bcea57afc3 config: Add ability to exit simulation after initialization
When using gem5 as a slave simulator, it will not advance the
clock on its own and depends on the master simulator calling
simulate(). This new option lets us use the Python scripts
to do all the configuration while stopping short of actually
simulating anything.
2015-03-23 06:57:38 -04:00
Andreas Hansson
ecd4bad351 config: Add soak test for memtest.py
This patch adds a random option to memtest.py which allows the user to
easily test valid random tree topologies. The patch also adds a
wrapper script to run soak tests using the newly introduced option.

We also adjust the progress interval and progress limit check to make
the output less noisy, and avoid false positives.

Bring on the pain.
2015-03-19 04:06:18 -04:00
Chris Emmons
142ab40c4b config: Specify OS type and release on command line
This patch enables users to speficy --os-type on the command
line. This option is used to take specific actions for an OS type,
such as changing the kernel command line. This patch is part of the
Android KitKat enablement.
2015-03-19 04:06:14 -04:00
Andreas Hansson
40e678069f config: Fix DRAM rank option in sweep script
Align with changes in the common bits.
2015-03-19 04:06:08 -04:00
Rizwana Begum
0c8e025c3b config: Fix for 'android' lookup in disk name
This patch modifies FSConfig.py to look for 'android' only in disk
image name. Before this patch, 'android' was searched in full
disk path.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-03-09 09:39:08 -05:00