Liao Xiongfei has uploaded this change for review. (
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 ( curTick() == 0 ) { //the first thread
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)));
}
...
For the first thread, the activateContext() is called at tick 0 while the
other cloned
threads are not at tick 0.
For the cloned thread, the above bug fix delays the execution of
pipeline->wakeupFetch()
after the OS::archClone is done.
A member variable fetchEventWrapper is added to MinorCPU class for delayed
fetch event.
A few previously failed RISC-V ASM tests have been open after the bug fix
works.
JIRA issue: https://gem5.atlassian.net/browse/GEM5-374
Change-Id: Ibffe46522e2617443d29f49df180692c54830f14
---
M src/cpu/minor/cpu.cc
M src/cpu/minor/cpu.hh
M tests/gem5/asmtest/tests.py
3 files changed, 29 insertions(+), 15 deletions(-)
diff --git a/src/cpu/minor/cpu.cc b/src/cpu/minor/cpu.cc
index 18a3fee..1d6b1fe 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 +271,15 @@
/* Wake up the thread, wakeup the pipeline tick */
threads[thread_id]->activate();
wakeupOnEvent(Minor::Pipeline::CPUStageId);
- pipeline->wakeupFetch(thread_id);
+ if ( curTick() == 0 ) { //the first thread
+ 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/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',
--
To view, visit https://gem5-review.googlesource.com/c/public/gem5/+/37315
To unsubscribe, or for help writing mail filters, visit
https://gem5-review.googlesource.com/settings
Gerrit-Project: public/gem5
Gerrit-Branch: develop
Gerrit-Change-Id: Ibffe46522e2617443d29f49df180692c54830f14
Gerrit-Change-Number: 37315
Gerrit-PatchSet: 1
Gerrit-Owner: Liao Xiongfei <xiongfei.l...@gmail.com>
Gerrit-MessageType: newchange
_______________________________________________
gem5-dev mailing list -- gem5-dev@gem5.org
To unsubscribe send an email to gem5-dev-le...@gem5.org
%(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s
