Commit graph

11385 commits

Author SHA1 Message Date
Andreas Hansson
7d4e89d4e0 mem: Avoid adding and then removing empty snoop-filter items
This patch tidies up how we access the snoop filter for snoops, and
avoids adding items only to later remove them.
2015-09-25 07:26:57 -04:00
Andreas Hansson
ca163a80e2 mem: Only track snooping ports in the snoop filter
This patch changes the tracking of ports in the snoop filter to use
local dense port IDs so that we can have 64 snooping ports (rather
than crossbar slave ports). This is achieved by adding a simple
remapping vector that translates the actal port IDs into the local
slave IDs used in the SnoopMask.

Ultimately this patch allows us to scale to much larger systems
without introducing a hierarchy of crossbars.
2015-09-25 07:26:57 -04:00
Ali Jafri
3aa87251d7 mem: Add snoop filters to L2 crossbars, and check size
This patch adds a snoop filter to the L2XBar. For now we refrain from
globally adding a snoop filter to the SystemXBar, since the latter is
also used in systems without caches. In scenarios without caches the
snoop filter will not see any writeback/clean evicts from the CPU
ports, despite the fact that they are snooping. To avoid inadvertent
use of the snoop filter in these cases we leave it out for now.

A size check is added to the snoop filter, merely to ensure it does
not grow beyond the total capacity of the caches above it. The size
has to be set manually, and a value of 8 MByte is choosen as suitably
high default.
2015-09-25 07:26:57 -04:00
Andreas Hansson
0c5a98f9d1 mem: Store snoop filter lookup result to avoid second lookup
This patch introduces a private member storing the iterator from the
lookupRequest call, such that it can be re-used when the request
eventually finishes. The method previously called updateRequest is
renamed finishRequest to make it more clear that the two functions
must be called together.
2015-09-25 07:26:57 -04:00
Ali Jafri
ceec2bb02c mem: Add snoops for CleanEvicts and Writebacks in atomic mode
This patch mirrors the logic in timing mode which sends up snoops to
check for cached copies before sending CleanEvicts and Writebacks down
the memory hierarchy. In case there is a copy in a cache above,
discard CleanEvicts and set the BLOCK_CACHED flag in Writebacks so
that writebacks do not reset the cache residency bit in the snoop
filter below.
2015-09-25 07:26:57 -04:00
Ali Jafri
6ac356f93b mem: Add CleanEvict and Writeback support to snoop filters
This patch adds the functionality to properly track CleanEvicts and
Writebacks in the snoop filter. Previously there were no CleanEvicts, and
Writebacks did not send up snoops to ensure there were no copies in
caches above. Hence a writeback could never erase an entry from the
snoop filter.

When a CleanEvict message reaches a snoop filter, it confirms that the
BLOCK_CACHED flag is not set and resets the bits corresponding to the
CleanEvict address and port it arrived on. If none of the other peer
caches have (or have requested) the block, the snoop filter forwards
the CleanEvict to lower levels of memory. In case of a Writeback
message, the snoop filter checks if the BLOCK_CACHED flag is not set
and only then resets the bits corresponding to the Writeback
address. If any of the other peer caches have (or has requested) the
same block, the snoop filter sets the BLOCK_CACHED flag in the
Writeback before forwarding it to lower levels of memory heirarachy.
2015-09-25 07:26:57 -04:00
Ali Jafri
79d3dbcea8 mem: Add check for snooping ports in the snoop filter
This patch prevents the snoop filter from creating items for requests
originating from non-snooping ports. The allocation decision is thus
based both on the cacheability of the line, and the snooping status of
the source port. Ultimately we should check if the source of the
packet is caching, since also the CPU ports are snooping (but not
allocating). Thus, at the moment we rely on the snoop filter being
used together with caches.

The patch also transitions to use the Packet::getBlockAddr in
determining the line address.
2015-09-25 07:26:57 -04:00
Andreas Hansson
462c288a75 mem: Make the coherent crossbar account for timing snoops
This patch introduces the concept of a snoop latency. Given the
requirement to snoop and forward packets in zero time (due to the
coherency mechanism), the latency is accounted for later.

On a snoop, we establish the latency, and later add it to the header
delay of the packet. To allow multiple caches to contribute to the
snoop latency, we use a separate variable in the packet, and then take
the maximum before adding it to the header delay.
2015-09-25 07:13:54 -04:00
Andreas Hansson
3bd78a141e mem: Do not include snoop-filter latency in crossbar occupancy
This patch ensures that the snoop-filter latency only contributes to
the packet latency, and not to the crossbar throughput/occupancy. In
essence we treat the snoop-filter lookup as pipelined.
2015-09-25 06:45:52 -04:00
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
Nilay Vaish
4647e4e961 ruby: simple network: refactor code
Drops an unused variable and marks three variables as const.
2015-09-24 08:41:24 -05:00
Nilay Vaish
b3a3b0b6cf ruby: garnet: refactor code in network links 2015-09-23 11:23:11 -05:00
Nilay Vaish
6bd7aa1f20 ruby: bloom filters: refactor code 2015-09-23 11:23:10 -05:00
Nilay Vaish
c2376918a5 ruby: abstract controller: mark some variables as const 2015-09-23 11:23:10 -05:00
Wendy Elsasser
61c38524ce mem: Add initial HBM configurations
Created the following HBM configurations:
1) HBM gen1 (x128/CH), 2Gb die, 4H stack, 1Gbps, 8 channels
2) HBM gen2 (x64/PC), 8Gb die, 4H stack, 1Gbps, 16 pseudo-channels

The configuration values are based on:
- The HBM gen1 public JEDEC spec
- Publically released data from MemCon presentations
- Timing extrapolated from existing LPDDR configurations

Will adjust once specs become available.
2015-09-22 13:17:53 -05:00
Nilay Vaish
8975053864 ruby: garnet: mark some variables as const 2015-09-18 13:27:48 -05:00
Nilay Vaish
96c999fe88 ruby: print addresses in hex
Changeset 4872dbdea907 replaced Address by Addr, but did not make changes to
print statements.  So the addresses which were being printed in hex earlier
along with their line address, were now being printed in decimals.  This patch
adds a function printAddress(Addr) that can be used to print the address in hex
along with the lines address.  This function has been put to use in some of the
places.  At other places, change has been made to print just the address in
hex.
2015-09-18 13:27:47 -05:00
Nilay Vaish
216529bf18 ruby: slicc: derive DataMember class from Var instead of PairContainer
The DataMember class in Type.py was being derived from PairContainer.  A
separate Var object was also created for the DataMember.  This meant some
duplication of across the members of these two classes (Var and DataMember).
This patch changes DataMember from Var instead.  There is no obvious reason to
derive from PairContainer which can only hold pairs, something that Var class
already supports.  The only thing that DataMember has over Var is init_code,
which is being retained.  This change would later on help in having pointers
in DataMembers.
2015-09-18 13:27:47 -05:00
Tony Gutierrez
b3eb0d1423 ruby: update WireBuffer API to match that of MessageBuffer
this patch updates the WireBuffer API to mirror the changes in revision 11111
2015-09-17 14:00:33 -04:00
Nilay Vaish
928d4b4ba8 stats: updates due to changes to MOESI_hammer 2015-09-16 22:17:54 -05:00
Lena Olson
3225379cc0 ruby: Add missing block deallocations in MOESI_hammer
Some blocks in MOESI hammer were not getting deallocated when they were set to
an idle state (e.g. by invalidate or other_getx/s messages).  While
functionally correct, this caused some bad effects on performance, such as
blocks in I in the L1s getting sent to the L2 upon eviction, in turn evicting
valid blocks.  Also, if a valid block was in LRU, that block could be evicted
rather than a block in I.  This patch adds in the missing deallocations.

Committed by: Nilay Vaish<nilay@cs.wisc.edu>
2015-09-16 20:18:40 -05:00
Joe Gross
950e431d87 ruby: fix message buffer init order
The recent changes to make MessageBuffers SimObjects required them to be
initialized in a particular order, which could break some protocols. Fix this
by calling initNetQueues on the external nodes of each external link in the
constructor of Network.

This patch also refactors the duplicated code for checking network allocation
and setting net queues (which are called by initNetQueues) from the simple and
garnet networks to be in Network.
2015-09-16 13:10:42 -04:00
Nilay Vaish
c5058c0c00 stats: slight changes to MOESI_CMP_token.
Due slight change to latency for the reissue table.
2015-09-16 11:59:57 -05:00
Nilay Vaish
cd9e445813 ruby: message buffer, timer table: significant changes
This patch changes MessageBuffer and TimerTable, two structures used for
buffering messages by components in ruby.  These structures would no longer
maintain pointers to clock objects.  Functions in these structures have been
changed to take as input current time in Tick.  Similarly, these structures
will not operate on Cycle valued latencies for different operations.  The
corresponding functions would need to be provided with these latencies by
components invoking the relevant functions.  These latencies should also be
in Ticks.

I felt the need for these changes while trying to speed up ruby.  The ultimate
aim is to eliminate Consumer class and replace it with an EventManager object in
the MessageBuffer and TimerTable classes.  This object would be used for
scheduling events.  The event itself would contain information on the object and
function to be invoked.

In hindsight, it seems I should have done this while I was moving away from use
of a single global clock in the memory system.  That change led to introduction
of clock objects that replaced the global clock object.  It never crossed my
mind that having clock object pointers is not a good design.  And now I really
don't like the fact that we have separate consumer, receiver and sender
pointers in message buffers.
2015-09-16 11:59:56 -05:00
Nilay Vaish
78a1245b41 ruby: remove unused function removeRequest() 2015-09-16 11:59:55 -05:00
Nilay Vaish
4b19e06644 ruby: sequencer: remove commented out function printProgress() 2015-09-16 11:59:55 -05:00
David Hashe
b6b972da99 ruby: rename System.{hh,cc} to RubySystem.{hh,cc}
The eventual aim of this change is to pass RubySystem pointers through to
objects generated from the SLICC protocol code.

Because some of these objects need to dereference their RubySystem pointers,
they need access to the System.hh header file.

In src/mem/ruby/SConscript, the MakeInclude function creates single-line header
files in the build directory that do nothing except include the corresponding
header file from the source tree.

However, SLICC also generates a list of header files from its symbol table, and
writes it to mem/protocol/Types.hh in the build directory. This code assumes
that the header file name is the same as the class name.

The end result of this is the many of the generated slicc files try to include
RubySystem.hh, when the file they really need is System.hh. The path of least
resistence is just to rename System.hh to RubySystem.hh.

--HG--
rename : src/mem/ruby/system/System.cc => src/mem/ruby/system/RubySystem.cc
rename : src/mem/ruby/system/System.hh => src/mem/ruby/system/RubySystem.hh
2015-09-16 12:03:03 -04:00
Anthony Gutierrez
3edadb0bd3 slicc: export uint64_t instead of uint64 2015-09-16 12:01:39 -04:00
Jason Lowe-Power
fdf2a6f439 stats: files for regression tests for Learning gem5 scripts
Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-09-16 09:35:36 -05:00
Jason Lowe-Power
29dd04cfe9 tests: Add tests for the Learning gem5 scripts
These tests will ensure that Learning gem5 scripts are always up to date with
the changes in the mainline of gem5.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-09-16 09:35:36 -05:00
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
0d6a6dfd7b stats: updates due to recent changesets including d0934b57735a 2015-09-15 08:14:09 -05:00
Palle Lyckegaard
3de9def6c1 sparc: writing to tick_cmpr should not cause a panic
This register is writable according to UA2005

Tried to boot NetBSD which starts the kernel by writing to the tick_cmpr
register.  Without the patch gem5 crashes with a panic.  With the patch NetBSD
starts to boot normally (although sun4v support in NetBSD is not complete yet)

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-09-15 08:14:07 -05:00
Dongxue Zhang
58ec70444d dev: IDE Disk: Handle bad IDE image size
Handle bad IDE disk image size 0. When image size is 0, gem5 will cause an
exception with log "Floating point exception (core dumped)".

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-09-15 08:14:07 -05:00
Abdul Mutaal Ahmad
8dfa45e03c misc: Bugfix for Freezing Terminal in SystemC Simulation
If the terminal was used in the SystemC or TLM simulations the simulation gets
in a deadlock state. This is because of the Event queue gets locked while
servicing the async events leading to event queue deadlock. This was solved by
locking the queue at the beginning of service of async events.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-09-15 08:14:07 -05:00
Abdul Mutaal Ahmad
1bb6a100ab misc: Bugfix in TLM integration regarding CleanEvict Command
The CleanEvict command was not considered in /util/tlm/sc_port.cc this could
lead to a simulator crash. This issue is solved by ignoring this special
command type.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-09-15 08:14:07 -05:00
Andrew Lukefahr
543efd5ca6 cpu: pred: Local Predictor Reset in Tournament Predictor
When a branch gets squashed, it's speculative branch predictor state should get
rolled back in squash().  However, only the globalHistory state was being
rolled back.  This patch adds (at least some) support for rolling back the
local predictor state also.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-09-15 08:14:07 -05:00
Hongil Yoon
fb0f9884e2 cpu, o3: consider split requests for LSQ checksnoop operations
This patch enables instructions in LSQ to track two physical addresses for
corresponding two split requests. Later, the information is used in
checksnoop() to search for/invalidate the corresponding LD instructions.

The current implementation has kept track of only the physical address that is
referenced by the first split request. Thus, for checksnoop(), the line
accessed by the second request has not been considered, causing potential
correctness issues.

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2015-09-15 08:14:06 -05:00
Nilay Vaish
6bee1d9124 ruby: topology: refactor code. 2015-09-14 10:14:50 -05:00
Nilay Vaish
4e898be762 ruby: slicc: remove member buffer_expr from Var class
This was added by changeset 51f40b101a56.  Instead, buffer_expr would now be
associated with the InPort class.
2015-09-14 10:04:55 -05:00
Nilay Vaish
78bf2dfeac merged with 62e1504b9c64 2015-09-12 16:23:47 -05:00
Nilay Vaish
8b199b775e ruby: perfect switch: refactor code
Refactored the code in operateVnet(), moved partly to a new function
operateMessageBuffer().  This is required since a later patch moves to having a
wakeup event per MessageBuffer instead of one event for the entire Switch.
2015-09-12 16:16:17 -05:00
Nilay Vaish
25cd13dbf1 ruby: simple network: store Switch* in PerfectSwitch and Throttle
There are two reasons for doing so:

a. provide a source of clock to PerfectSwitch. A follow on patch removes sender
and receiver pointers from MessageBuffer means that the object owning the
buffer should have some way of providing timing info.

b. schedule events.  A follow on patch removes the consumer class.  So the
PerfectSwitch needs some EventManager object to schedule events on its own.
2015-09-12 16:16:03 -05:00
Andreas Sandberg
a151786741 dev: Add an underrun statistic to the HDLCD controller
Add a stat that counts buffer underruns in the HDLCD controller. The
stat counts at most one underrun per frame since the controller aborts
the current frame if it underruns.
2015-09-11 15:56:09 +01:00
Andreas Sandberg
f7055e9215 dev, arm: Rewrite the HDLCD controller
Rewrite the HDLCD controller to use the new DMA engine and pixel
pump. This fixes several bugs in the current implementation:

   * Broken/missing interrupt support (VSync, underrun, DMA end)
   * Fragile resolution changes (changing resolutions used
     to cause assertion errors).
   * Support for resolutions with a width that isn't divisible by 32.
   * The pixel clock can now be set dynamically.

This breaks checkpoint compatibility. Checkpoints can be upgraded with
the checkpoint conversion script. However, upgraded checkpoints won't
contain the state of the current frame. That means that HDLCD
controllers restoring from a converted checkpoint immediately start
drawing a new frame (i.e, expect timing differences).
2015-09-11 15:55:46 +01:00
Nilay Vaish
f611d4f22e ruby: slicc: remove nextLineHack from Type.py 2015-09-08 19:32:04 -05:00
Nilay Vaish
bc5be9ac43 config: allow ruby to be used with Minor CPU 2015-09-06 23:11:11 -05:00
Nilay Vaish
740984b30b ruby: call setMRU from L1 controllers, not from sequencer
Currently the sequencer calls the function setMRU that updates the replacement
policy structures with the first level caches.  While functionally this is
correct, the problem is that this requires calling findTagInSet() which is an
expensive function.  This patch removes the calls to setMRU from the sequencer.
All controllers should now update the replacement policy on their own.

The set and the way index for a given cache entry can be found within the
AbstractCacheEntry structure. Use these indicies to update the replacement
policy structures.
2015-09-05 09:35:39 -05:00
Nilay Vaish
8f29298bc7 ruby: adds set and way indices to AbstractCacheEntry 2015-09-05 09:35:31 -05:00
Nilay Vaish
abcc67010e ruby: set: reimplement using std::bitset
The current Set data structure is slow and therefore is being reimplemented
using std::bitset. A maximum limit of 64 is being set on the number of
controllers of each type.  This means that for simulating a system with more
controllers of a given type, one would need to change the value of the variable
NUMBER_BITS_PER_SET
2015-09-05 09:34:25 -05:00