Re: [Gems-users] Error with a CMP configuration

[Mike Marty <mikem@xxxxxxxxxxx>]

Also if you wanted, you can get (us) more info about this deadlock through
a debug trace.  I'm not sure if any of us can devote time to fixing a
possibly protocol bug, but if we can't reproduce the bug or can't see a
trace there is not much we can do.

The deadlock detection tool showed that a request for 0xff242640, which
started at time 894780000 is possibly deadlocked.

A debug trace can be triggered just before this request with the following
Simics commands:

ruby0.debug-output-file my_deadlock_trace.txt
ruby0.debug-start-time "894770000"

This starts the trace 10000 cycles before the deadlocked request starts
hopefully capturing all the information of this block before and during
the request.  Nonetheleses, the output file will be quite large.

--Mike


> hi
> I am sorry , I should have included this in the ealier email,
> MSI_MOSI_CMP_directory is the protocol .
> It might be a bug, I was reading throught the sequencer code, It mainly
> handles consistency stuff, could you let me know the conditiions under
> which the error might be thrown, I can then put all the pieces together
> salil
>
> Mike Marty wrote:
>
> >Which protocol?  Our CMP protocols included with the release are
> >MOESI_CMP_token, MSI_MOSI_CMP_directory, and MOESI_CMP_directory.  The
> >latter two are especially complex and you might have uncovered a bug.
> >
> >--Mike
> >
> >
> >
> >
> >>hi,
> >>    I am using ruby to setup a CMP 32 processor system (16 CMP's) along
> >>with simics. I got the following error (only while running 32 threads, a
> >>configuration with lesser threads seems to run fine )
> >>Warning: in fn virtual void Sequencer::wakeup() in
> >>system/Sequencer.C:119: Possible Deadlock detected
> >>Warning: in fn virtual void Sequencer::wakeup() in
> >>system/Sequencer.C:119: Possible Deadlock detected
> >>Warning: in fn virtual void Sequencer::wakeup() in
> >>system/Sequencer.C:120: request is [CacheMsg: Address=[0xb93ae54, line
> >>0xb93ae40] Type=ATOMIC ProgramCounter=[0xff242660, line 0xff242640]
> >>AccessMode=UserMode Size=1 Prefetch=No Version=0 Aborted=0 Time=894780000 ]
> >>Warning: in fn virtual void Sequencer::wakeup() in
> >>system/Sequencer.C:120: request is [CacheMsg: Address=[0xb93ae54, line
> >>0xb93ae40] Type=ATOMIC ProgramCounter=[0xff242660, line 0xff242640]
> >>AccessMode=UserMode Size=1 Prefetch=No Version=0 Aborted=0 Time=894780000 ]
> >>
> >>Warning: in fn virtual void Sequencer::wakeup() in
> >>system/Sequencer.C:125: keys.size() is 1
> >>Warning: in fn virtual void Sequencer::wakeup() in
> >>system/Sequencer.C:126: *m_writeRequestTable_ptr is [ [0xb93ae40, line
> >>0xb93ae40]=[CacheMsg: Address=[0xb93ae54, line 0xb93ae40] Type=ATOMIC
> >>ProgramCounter=[0xff242660, line 0xff242640] AccessMode=UserMode Size=1
> >>Prefetch=No Version=0 Aborted=0 Time=894780000 ] ]
> >>Warning: in fn virtual void Sequencer::wakeup() in
> >>system/Sequencer.C:126: *m_writeRequestTable_ptr is [ [0xb93ae40, line
> >>0xb93ae40]=[CacheMsg: Address=[0xb93ae54, line 0xb93ae40] Type=ATOMIC
> >>ProgramCounter=[0xff242660, line 0xff242640] AccessMode=UserMode Size=1
> >>Prefetch=No Version=0 Aborted=0 Time=894780000 ] ]
> >>Fatal Error: in fn virtual void Sequencer::wakeup() in
> >>system/Sequencer.C:127: Aborting
> >>Fatal Error: in fn virtual void Sequencer::wakeup() in
> >>system/Sequencer.C:127: Aborting
> >>***  Simics getting shaky, switching to 'safe' mode.
> >>***  Simics (main thread) received an abort signal, probably an assertion.
> >><Simics is running in 'safe' mode>
> >>
> >>My configuration is pretty standard , I am using PT_TO_POINT topology
> >>network. I havent made any changes in the ruby code . The program is a
> >>simple LU benchmark from the splash 2 suite.
> >>I am using simics 2.0.16 on host x86-linux.
> >>Can you give me some idea about this error so that I can try to fix it.
> >>salil
> >>_______________________________________________
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> >>Gems-users@xxxxxxxxxxx
> >>https://lists.cs.wisc.edu/mailman/listinfo/gems-users
> >>
> >>
> >>
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> >
> >
>
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