All over gem5 the params pointers are not deleted within the classes
that they were created for. Although this is a potential memory leak
as of now, it is probably safer to follow general convention so that
it can be fixed at once in the future.
Change-Id: If96f04058d51513fa8763610880e5524785ee9cf
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24249
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
All over gem5 the params pointers are not deleted within the classes
that they were created for. Although this is a potential memory leak
as of now, it is probably safer to follow general convention so that
it can be fixed at once in the future.
Change-Id: I74b662a8e635cdfb4dc1eae732dd114659fab2e9
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24246
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
While the up-to-date data may reside in any agent of Ruby's memory
hierarchy, there's an optional backing store in Ruby that provides
a 'correct' view of the physical memory. When it is enabled by the
user, every Ruby memory access will update this global memory view
as well upon finishing.
The issue is that Ruby's atomic access, used in fast-forward, does
not currently access the backing store, leading to data
incorrectness. More specifically, at the very beginning stage of the
simulation, a loader loads the program into the backing store using
functional accesses. Then the program starts execution with
fast-forward enabled, using atomic accesses for faster simulation. But
because atomic access only accesses the real memory hierarchy, the CPU
fetches incorrect instructions.
The fix is simple. Just make Ruby's atomic access update the backing
store as well as the real physical memory.
Change-Id: I2541d923e18ea488d383097ca7abd4124e47e59b
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/26343
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Onur Kayıran <onur.kayiran@amd.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This patch was created by Bihn Pham during his internship at AMD.
This patch fixes a very significant performance bug when using the O3
CPU model and Ruby. The issue was Ruby returned false when it received
a request to the same address that already has an outstanding request or
when the memory is blocked. As a result, O3 unnecessary squashed the
pipeline and re-executed instructions. This fix merges readRequestTable
and writeRequestTable in Sequencer into a single request table that
keeps track of all requests and allows multiple outstanding requests to
the same address. This prevents O3 from squashing the pipeline.
Change-Id: If934d57b4736861e342de0ab18be4feec464273d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21219
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Add support in Ruby to use all replacement policies in Classic.
Furthermore, if new replacement policies are added to the
Classic system, the Ruby system will recognize new policies
without any other changes in Ruby system. The following list
all the major changes:
* Make Ruby cache entries (AbstractCacheEntry) inherit from
Classic cache entries (ReplaceableEntry). By doing this,
replacement policies can use cache entries from Ruby caches.
AccessPermission and print function are moved from
AbstractEntry to AbstractCacheEntry, so AbstractEntry is no
longer needed.
* DirectoryMemory and all SLICC files are changed to use
AbstractCacheEntry as their cache entry interface. So do the
python files in mem/slicc/ast which check the entry
interface.
* "main='false'" argument is added to the protocol files where
the DirectoryEntry is defined. This change helps
differentiate DirectoryEntry from CacheEntry because they are
both the instances of AbstractCacheEntry now.
* Use BaseReplacementPolicy in Ruby caches instead of
AbstractReplacementPolicy so that Ruby caches will recognize
the replacement policies from Classic.
* Add getLastAccess() and useOccupancy() function to Classic
system so that Ruby caches can use them. Move lastTouchTick
to ReplacementData struct because it's needed by
getLastAccess() to return the correct value.
* Add a 2-dimensional array of ReplacementData in Ruby caches
to store information for different replacement policies. Note
that, unlike Classic caches, where policy information is
stored in cache entries, the policy information needs to be
stored in a new 2-dimensional array. This is due to Ruby
caches deleting the cache entry every time the corresponding
cache line get evicted.
Change-Id: Idff6fdd2102a552c103e9d5f31f779aae052943f
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20879
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The cacheProbe() function will return the victim entry, and it gets
called for multiple times in trigger function in a single miss. This
will cause a problem when we try to add a new replacement policy to
the Ruby system. Certain policy, like RRIP, will modify the block
information every time the getVictim() function gets called. To
prevent future problems, we need to store the victim entry, so that
we only call it once in one miss.
Change-Id: Ic5ca05f789d9bbfb963b8e993ef707020f243702
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21099
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Pouya Fotouhi <pfotouhi@ucdavis.edu>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
To ensure that enqueuer observes the practical availability. We
check the message buffer queue size at the start of the cycle.
We also add the size of the stall queue to consider the total
queue size. However, messages can be moved from regular queue
to stall map. This leads to messages being considered twice leading
to false flow control. This patch fixes it by storing the stall map
size at the beginning of the cycle and considering it for checking
availability.
Change-Id: I6ea94f34fe5279b91f74e106d43263e55ec4bf06
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20389
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Make MultiBitSelBloomFilter a generic BloomFilter that maps
multiple entries to an address, and therefore uses multiple
hash functions. This allows the common functionality of both
filters to be merged into one, since they only differ in the
hash functions being used.
Change-Id: I0984067b710a208715f5f2727b8c4312feb6529b
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18873
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Renamed member variables to comply with general naming
conventional outside of the ruby folder so that the
filters can be moved out.
Moved code to base to reduce code duplication.
Renamed the private get_index functions to hash, to make their
functionality explicit.
Change-Id: Ic6519cfc5e09ea95bc502a29b27f750f04eda754
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18734
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Most of the index based functions were not implemented, and a
user is more likely to be interested in checking the filter
contents based on an address than an index.
As a side effect, the Bulk's hash function became unused, and
according to the paper permute() was doing more than just
permuting, so it was renamed.
Change-Id: I6423a2565a082fee2e7f11fa489a11f253064d99
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/18732
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
