Liao Xiongfei has submitted this change. (
https://gem5-review.googlesource.com/c/public/gem5/+/37315 )
Change subject: cpu-minor: this is a bug fix for MinorCPU for thread
cloning.
......................................................................
cpu-minor: this is a bug fix for MinorCPU for thread cloning.
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 <bbr...@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbr...@ucdavis.edu>
Tested-by: kokoro <noreply+kok...@google.com>
---
M src/cpu/minor/cpu.cc
M src/cpu/minor/cpu.hh
M src/cpu/thread_context.hh
M src/sim/syscall_emul.hh
M tests/gem5/asmtest/tests.py
5 files changed, 41 insertions(+), 15 deletions(-)
Approvals:
Bobby R. Bruce: Looks good to me, approved; Looks good to me, approved
kokoro: Regressions pass
diff --git a/src/cpu/minor/cpu.cc b/src/cpu/minor/cpu.cc
index 18a3fee..de74256 100644
--- a/src/cpu/minor/cpu.cc
+++ b/src/cpu/minor/cpu.cc
@@ -77,12 +77,17 @@
pipeline = new Minor::Pipeline(*this, params);
activityRecorder = pipeline->getActivityRecorder();
+
+ fetchEventWrapper = NULL;
}
MinorCPU::~MinorCPU()
{
delete pipeline;
+ if (fetchEventWrapper != NULL)
+ delete fetchEventWrapper;
+
for (ThreadID thread_id = 0; thread_id < threads.size(); thread_id++) {
delete threads[thread_id];
}
@@ -266,7 +271,17 @@
/* Wake up the thread, wakeup the pipeline tick */
threads[thread_id]->activate();
wakeupOnEvent(Minor::Pipeline::CPUStageId);
- pipeline->wakeupFetch(thread_id);
+
+ 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)));
+ }
BaseCPU::activateContext(thread_id);
}
diff --git a/src/cpu/minor/cpu.hh b/src/cpu/minor/cpu.hh
index ac9831a..0e919f33 100644
--- a/src/cpu/minor/cpu.hh
+++ b/src/cpu/minor/cpu.hh
@@ -186,6 +186,7 @@
* already been idled. The stage argument should be from the
* enumeration Pipeline::StageId */
void wakeupOnEvent(unsigned int stage_id);
+ EventFunctionWrapper *fetchEventWrapper;
};
#endif /* __CPU_MINOR_CPU_HH__ */
diff --git a/src/cpu/thread_context.hh b/src/cpu/thread_context.hh
index c50eb26..2cad1ac 100644
--- a/src/cpu/thread_context.hh
+++ b/src/cpu/thread_context.hh
@@ -91,9 +91,17 @@
using VecRegContainer = TheISA::VecRegContainer;
using VecElem = TheISA::VecElem;
using VecPredRegContainer = TheISA::VecPredRegContainer;
+ bool useForClone = false;
public:
+ bool getUseForClone() { return useForClone; }
+
+ void setUseForClone(bool newUseForClone)
+ {
+ useForClone = newUseForClone;
+ }
+
enum Status
{
/// Running. Instructions should be executed only when
diff --git a/src/sim/syscall_emul.hh b/src/sim/syscall_emul.hh
index 7d7e265..491a309 100644
--- a/src/sim/syscall_emul.hh
+++ b/src/sim/syscall_emul.hh
@@ -1480,6 +1480,8 @@
cp->pTable->shared = true;
cp->useForClone = true;
}
+
+ ctc->setUseForClone(true);
cp->initState();
p->clone(tc, ctc, cp, flags);
diff --git a/tests/gem5/asmtest/tests.py b/tests/gem5/asmtest/tests.py
index b2a9249..026b230 100755
--- a/tests/gem5/asmtest/tests.py
+++ b/tests/gem5/asmtest/tests.py
@@ -41,7 +41,7 @@
cpu_type,
num_cpus=4,
max_tick=10000000000,
- ruby=True,
+ ruby=False,
debug_flags=None, # Debug flags passed to gem5
full_system = False
):
@@ -96,10 +96,10 @@
# https://gem5.atlassian.net/browse/GEM5-496
# https://gem5.atlassian.net/browse/GEM5-497
binaries = (
-# 'rv64samt-ps-sysclone_d',
-# 'rv64samt-ps-sysfutex1_d',
+ 'rv64samt-ps-sysclone_d',
+ 'rv64samt-ps-sysfutex1_d',
# 'rv64samt-ps-sysfutex2_d',
-# 'rv64samt-ps-sysfutex3_d',
+ 'rv64samt-ps-sysfutex3_d',
# 'rv64samt-ps-sysfutex_d',
'rv64ua-ps-amoadd_d',
'rv64ua-ps-amoadd_w',
@@ -120,16 +120,16 @@
'rv64ua-ps-amoxor_d',
'rv64ua-ps-amoxor_w',
'rv64ua-ps-lrsc',
-# 'rv64uamt-ps-amoadd_d',
-# 'rv64uamt-ps-amoand_d',
-# 'rv64uamt-ps-amomax_d',
-# 'rv64uamt-ps-amomaxu_d',
-# 'rv64uamt-ps-amomin_d',
-# 'rv64uamt-ps-amominu_d',
-# 'rv64uamt-ps-amoor_d',
-# 'rv64uamt-ps-amoswap_d',
-# 'rv64uamt-ps-amoxor_d',
-# 'rv64uamt-ps-lrsc_d',
+ 'rv64uamt-ps-amoadd_d',
+ 'rv64uamt-ps-amoand_d',
+ 'rv64uamt-ps-amomax_d',
+ 'rv64uamt-ps-amomaxu_d',
+ 'rv64uamt-ps-amomin_d',
+ 'rv64uamt-ps-amominu_d',
+ 'rv64uamt-ps-amoor_d',
+ 'rv64uamt-ps-amoswap_d',
+ 'rv64uamt-ps-amoxor_d',
+ 'rv64uamt-ps-lrsc_d',
'rv64ud-ps-fadd',
'rv64ud-ps-fclass',
'rv64ud-ps-fcmp',
--
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Gerrit-Project: public/gem5
Gerrit-Branch: develop
Gerrit-Change-Id: Ibffe46522e2617443d29f49df180692c54830f14
Gerrit-Change-Number: 37315
Gerrit-PatchSet: 9
Gerrit-Owner: Liao Xiongfei <xiongfei.l...@gmail.com>
Gerrit-Reviewer: Bobby R. Bruce <bbr...@ucdavis.edu>
Gerrit-Reviewer: Gabe Black <gabe.bl...@gmail.com>
Gerrit-Reviewer: Giacomo Travaglini <giacomo.travagl...@arm.com>
Gerrit-Reviewer: Jason Lowe-Power <power...@gmail.com>
Gerrit-Reviewer: Liao Xiongfei <xiongfei.l...@gmail.com>
Gerrit-Reviewer: Nils Asmussen <nils.asmus...@barkhauseninstitut.org>
Gerrit-Reviewer: ZHENGRONG WANG <seanyukig...@gmail.com>
Gerrit-Reviewer: kokoro <noreply+kok...@google.com>
Gerrit-MessageType: merged
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