When building with clang with the --without-tcmalloc flag set, the
-fno-builtin flag is not used, and clang can then detect that the
integer version of abs(), apparently the C version, is being used on a
floating point value in traffic_gen.cc.
This change takes clang's suggestion to use std::abs instead, and also
includes a header file which will provide it.
Change-Id: Ic28ed7454b2ac00c89328d9d0314aed74e946643
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/41597
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Add a DMA thread tester to the Ruby GPU tester to test the DMA state
machine in the protocol. Currently creates a dummy DMA device to pass
through Ruby.py and scans for the DMA sequencers due to opaqueness of
Ruby.py.
DMA atomics not yet supported as there is no protocol that implements
atomic transitions in the DMA state machine file.
Example run command:
build/GCN3_X86/gem5.opt configs/example/ruby_gpu_random_test.py \
--test-length=1000
Change-Id: I63d83e00fd0dcbb1e34c6704d1c2d49ed4e77722
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/39936
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Matt Sinclair <mattdsinclair@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This DPRINTF accesses the ExtMachInst typed machInst member of the
StaticInst class, and so is ISA dependent. Move the DPRINTF to where the
instructions are actually decoded where that type doesn't have to be
disambiguated.
Also, this change makes this DPRINTF more accurate, since microops are
not really "decoded" when they are extracted from a macroop. The process
of unpacking them to feed into the rest of the CPU should be fairly
trivial, so really they're just being retrieved. With the DPRINTF in
this new position, it will only trigger when an instruction is actually
decoded from memory.
Change-Id: I14145165b93bb004057a729fa7909cd2d3d34d29
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/40099
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The only way to allocate fixed sized arrays which will definitely be big
enough for all source/destination registers for a given instruction is
to track the maximum number of each at compile time, and then size the
arrays appropriately. That creates a point of centralization which
prevents breaking up decoder and instruction definitions into more
modular pieces, and if multiple ISAs are ever built at once, would
require coordination between all ISAs, and wasting memory for most of
them.
The dynamic allocation overhead is minimized by allocating the storage
for all variable arrays in one chunk, and then placing the arrays there
using placement new. There is still some overhead, although less than it
might be otherwise.
Change-Id: Id2c42869cba944deb97da01ca9e0e70186e22532
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/38384
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This takes the place of direct access to the machInst field as used in
the MinorCPU model which makes the incorrect assumption that it can
arbitrarily treat the ExtMachInst as an integer, and that masking in a
certain way can meaningfully classify what the instruction will do.
Because that assumption is not correct in general, that had been
ifdef-ed out in most ISAs except ARM, and for the other ISAs the value
was simply set to zero.
Change-Id: I8ac05e65475edc3ccc044afdff09490e2c05ba07
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/40098
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
This should help reduce warning spew when building with newer compilers.
The pybind11::module type has been renamed pybind11::module_ to avoid
conflicts with c++20 modules, according to the pybind11 changelog, so
this CL also updates gem5 source to use the new type. There is
supposedly an alias pybind11::module which is for compatibility, but we
still get linker errors without changing to pybind11::module_.
Change-Id: I0acb36215b33e3a713866baec43f5af630c356ee
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/40255
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
This was mostly not used to begin with, but also when it was used, it
would obscure places where there were types, functions, etc, which were
switched between ISAs at compile time, and which would need to be
cleaned up to allow more than one ISA at a time.
Change-Id: Ieb372feff91b7e946b477fb78e54bcd0c2138966
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/39655
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
This class had been trying to keep all indices within the modulus of the
queue size, and to use all elements in the underlying storage by making
the empty and full conditions alias, differentiated by a bool. To keep
track of the difference between a storage location on one trip around
the queue vs other times around, ie an alias once the indices had
wrapped, it also keep track of a "round" value in both the queue itself,
and any iterators it created.
All this bookkeeping significantly complicated the data structure.
Instead, this change modifies it to keep track of a monotonically
increasing index which is wrapped at the time it's used. Only the head
index and current size need to be tracked in the queue itself, and only
a pointer to the queue and an index need to be tracked in the iterators.
Theoretically, it's possible that this value could overflow eventually
since it increases forever, unlike before where the index wrapped and
was never larger than the queue's capacity. In practice, the type of the
index was changed from a uint32_t to a size_t, probably a 64 bit value
in modern systems, which will hold much larger values. Also, the round
counter and the index values together acted like a smaller than 64 bit
value anyway, since the round counter would overflow after 2^32 times
around a less than 2^32 entry queue.
One minor interface difference is that the head() and tail() values
returned by the queue are no longer pre-wrapped to be modulo the queue's
capacity. As long as consumers don't try to be overly clever and feed in
fixed values, do their own bounds checking, etc., something that would
be cumbersome considering the wrapping nature of the structure, this
shouldn't be an issue.
Also, since external consumers no longer need to worry about wrapping,
since only one of them was used in only one place, and because they
weren't even marked as part of the interface, the modulo helper
functions have been eliminated from the queue. If other code wants to
perform modulo arithmetic for some reason (which the queue no longer
requires) they can accomplish basically the same thing in basically the
same amount of code using normal math.
Also, rather than inherit from std::vector, this change makes the vector
internal to the queue. That prevents methods of the vector that aren't
aware of the circular nature of the structure from leaking out if
they're not overridden or otherwise proactively blocked.
On top of simplifying the implementation, this also makes it perform
*slightly* better. To measure that, I ran the following command:
$ time build/ARM/base/circular_queue.test.opt --gtest_repeat=100000 > /dev/null
and found a few percent improvement in total run time. While this
difference was small and not measured against realistic usage of the
data structure, it was still measurable, and at minimum doesn't seem to
have hurt performance.
Change-Id: Ic2baa28de135be7086fa94579bbec451d69b3b15
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/38478
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
When a gem5 op is triggered using a KVM MMIO exit event, the PC has
already been advanced beyond the offending instruction. Normally when
a system call or gem5 op is triggered, the PC has not advanced because
the instruction hasn't actually finished executing. This means that if
a gem5 op, and by extension a system call in SE mode, want to advance
the PC to the instruction after the gem5 op, they have to check whether
they were triggered from KVM.
To avoid having to special case these sorts of situations (currently
only in the clone system call), we can have the code which dispatches to
gem5 ops from KVM adjust the next PC so that it points to what the
current PC is. That way the PC can be advanced unconditionally, and will
point to the instruction after the one that triggered the call.
To be fully consistent, we would also need to adjust the current PC.
That would be non-trivial since we'd have to figure out where the
current instruction started, and that may not even be possible to
unambiguously determine given x86's instruction structure. Then we would
also need to restore the original PC to avoid confusing KVM.
Change-Id: I9ef90b2df8e27334dedc25c59eb45757f7220eea
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/38486
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Inside the code of cloneFunc(…) //syscall_emul.hh
cp->initState(); //line 1483
p->clone(tc, ctc, cp, flags); //line 1484
…
ctc->clearArchRegs(); //line 1503
OS::archClone(flags, p, cp, tc, ctc, newStack, tlsPtr); //line 1505
…
At line 1483, initState() is called and the activateContext() of the
corresponding MinorCPU is eventually called. The actual architecture
clone happens at line 1505 where PC of the new thread could have a
correct value.
In the existing implementation of MinorCPU::activateContext(ThreadID
thread_id), the below line 275 is called
pipeline->wakeupFetch(thread_id);
to start fetching instruction with current value of PC, which is 0x0,
leading to panic “Page table fault when accessing virtual address 0”.
This is because the OS::archClone() is not yet called. So, the below bug
fix handles the wakeup fetch for a thread for two scenarios:
...
if (!threads[thread_id]->getUseForClone())
{ //the thread is not cloned
pipeline->wakeupFetch(thread_id);
} else {//the thread from clone
if (fetchEventWrapper != NULL)
delete fetchEventWrapper;
fetchEventWrapper = new EventFunctionWrapper([this, thread_id]
{pipeline->wakeupFetch(thread_id);}, "wakeupFetch");
schedule(*fetchEventWrapper, clockEdge(Cycles(0)));
}
...
If a thread is not cloned, pipeline->wakeupFetch() is called
immediately.
For the cloned thread, the above bug fix delays the execution of
pipeline->wakeupFetch()
after the OS::archClone is done. ThreadContext::getUseForClone() return
true if a thread is cloned.
A member variable fetchEventWrapper is added to MinorCPU class for
delayed fetch event.
A member variable useForClone and its corresponding get/set methods are
added to ThreadContext class. This approach allows future reuse of this
useForClone variable by other CPU models if needed and also avoid lots
of changes resulted by modifying parameters of activateContext () and
activate() which are defined as override.
Inside the syscall cloneFunc, the useForClone member of a ThreadContext
object is set via its set method right before Process's initState() is
called, shown as below.
ctc->setUseForClone(true);
cp->initState();
p->clone(tc, ctc, cp, flags);
A few previously failed RISC-V ASM tests have been open in tests.py file
after the bug fix works.
JIRA issue: https://gem5.atlassian.net/browse/GEM5-374
Change-Id: Ibffe46522e2617443d29f49df180692c54830f14
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/37315
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
