The GPU device currently supports large BAR which means that the driver
can write directly to GPU memory over the PCI bus without using SDMA or
PM4 packets. The gem5 PCI interface only provides an atomic interface
for BAR reads/writes, which means the values cannot go through timing
mode Ruby caches. This causes bugs as the TCC cache is allowed to keep
clean data between kernels for performance reasons. If there is a BAR
write directly to memory bypassing the cache, the value in the cache is
stale and must be invalidated.
In this commit a TCC invalidate is generated for all writes over PCI
that go directly to GPU memory. This will also invalidate TCP along the
way if necessary. This currently relies on the driver synchonization
which only allows BAR writes in between kernels. Therefore, the cache
should only be in I or V state.
To handle a race condition between invalidates and launching the next
kernel, the invalidates return a response and the GPU command processor
will wait for all TCC invalidates to be complete before launching the
next kernel.
This fixes issues with stale data in nanoGPT and possibly PENNANT.
Change-Id: I8e1290f842122682c271e5508a48037055bfbcdf
A previous commit added BUILD_GPU guards to gpu coalescer models since
a related cache recorder commit added GPU support. This is no longer
needed since the cache recorder moved to using a vector of RubyPorts
instead of Sequencer/GPUCoalescer pointers. This commit removes
BUILD_GPU guards from the Ruby coalescer models
Change-Id: I23a7957d82524d6cd3483d22edfb35ac51796eca
Ruby was recently updated to support flushes and warmup for GPUs. Since
this support uses the GPUCoalescer, non-GPU builds face a compile time
issue. This is because GPU code is not built for non-GPU builds. This
commit addes "#if BUILD_GPU" guards around the GPU-related code in
common files like AbstractController.hh, CacheRecorder.*, RubySystem.cc,
GPUCoalescer.hh, and VIPERCoalescer.hh. This support allows GPU builds
to use flushing while non-GPU builds compile without problems
Change-Id: If8ee4ff881fe154553289e8c00881ee1b6e3f113
Remove the line "For use for simulation and test purposes only" in files
were AMD is the only copyright holder listed in the header. This happens
to be the case for all files where this line exists, removing it
completely from gem5.
Change-Id: I623f266b002f564301b28774f49081099cfc60fd
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/53943
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Apply the gem5 namespace to the codebase.
Some anonymous namespaces could theoretically be removed,
but since this change's main goal was to keep conflicts
at a minimum, it was decided not to modify much the
general shape of the files.
A few missing comments of the form "// namespace X" that
occurred before the newly added "} // namespace gem5"
have been added for consistency.
std out should not be included in the gem5 namespace, so
they weren't.
ProtoMessage has not been included in the gem5 namespace,
since I'm not familiar with how proto works.
Regarding the SystemC files, although they belong to gem5,
they actually perform integration between gem5 and SystemC;
therefore, it deserved its own separate namespace.
Files that are automatically generated have been included
in the gem5 namespace.
The .isa files currently are limited to a single namespace.
This limitation should be later removed to make it easier
to accomodate a better API.
Regarding the files in util, gem5:: was prepended where
suitable. Notice that this patch was tested as much as
possible given that most of these were already not
previously compiling.
Change-Id: Ia53d404ec79c46edaa98f654e23bc3b0e179fe2d
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/46323
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Matthew Poremba <matthew.poremba@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The mismatches were from places where Params structs had been declared
as classes instead of structs, and ruby's MachineID struct.
A comment describing why the warning had been disabled said that it was
because of libstdc++ version 4.8. As far as I can tell, that version is
old enough to be outside the window we support, and so that should no
longer be a problem. It looks like the oldest version of gcc we
support, 5.0, corresponds with approximately libstdc++ version 6.0.21.
https://gcc.gnu.org/onlinedocs/libstdc++/manual/abi.html#abi.versioning
Change-Id: I75ad92f3723a1883bd47e3919c5572a353344047
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/40953
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The create() method on Params structs usually instantiate SimObjects
using a constructor which takes the Params struct as a parameter
somehow. There has been a lot of needless variation in how that was
done, making it annoying to pass Params down to base classes. Some of
the different forms were:
const Params &
Params &
Params *
const Params *
Params const*
This change goes through and fixes up every constructor and every
create() method to use the const Params & form. We use a reference
because the Params struct should never be null. We use const because
neither the create method nor the consuming object should modify the
record of the parameters as they came in from the config. That would
make consuming them not idempotent, and make it impossible to tell what
the actual simulation configuration was since it would change from any
user visible form (config script, config.ini, dot pdf output).
Change-Id: I77453cba52fdcfd5f4eec92dfb0bddb5a9945f31
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35938
Reviewed-by: Gabe Black <gabeblack@google.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Standardize all header guards in the mem directory according to the most
frequent patterns. In general they have the form:
mem: __FOLDER_TREE_FILE_NAME_HH__
ruby: __FOLDER_TREE_FILENAME_HH__
Change-Id: I983853e292deb302becf151bf0e970057dc24774
Reviewed-on: https://gem5-review.googlesource.com/7881
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
