Hey Marc, Just wondering if there has been any progress on this. It looks like the Review and mwait test program conversations petered out about a year ago.
Thanks! Joel On Sat, Feb 16, 2013 at 3:56 PM, Marc Orr <marc....@gmail.com> wrote: > On review 1622 (http://reviews.gem5.org/r/1622/), a patch that implements > the x86 mwait instruction, I made the following comments: > > > *...* > > *2. I ran into minor issues testing the O3 in syscall emulation where I > > was running out of stack space. I think there is a bug somewhere in the > > simulator (or more likely m5threads), but I was able to hack around it > for > > testing purposes. This issue is orthogonal to this patch, so I hope to > not > > worry about it for now.* > > *3. While mwait does work in full system, testing it was a nightmare. > > This is because interrupts from a hardware timer and system calls trigger > > wakeups frequently. In fact, wakeups are triggered so frequently, that I > > suspect something may be wrong with fully system mode (maybe the timer is > > not running at the correct speed?). Again, this potential issue is > > orthogonal to this patch.* > > > > Nilay suggested that I document the exact issues I ran into. > > *With respect to issue #2:* > When I tested the patch, with a test program I wrote (which can be found in > review 1621, http://reviews.gem5.org/r/1621/), the simulator could not run > the program to completion because it ran out of stack space. See "*command > line for issue #2*" at the bottom of this email for the exact details. > > I was able to circumvent this issue, by setting the max_stack_size > parameter for the LiveProcess in configs/example/se.py to '0B'. I was > actually just experimenting when I tried this, but the test ran to > completion. See the "*hack for issue #2*" at the bottom of this email for a > patch that makes this modification. > > related threads: > http://comments.gmane.org/gmane.comp.emulators.m5.users/8035 > http://comments.gmane.org/gmane.comp.emulators.m5.devel/2281 > > *With respect to issue #3:* > I'm not able to recreate whatever I was talking about here. I actually > didn't mean for this comment to make it to review board as I didn't > understand the problems I was facing very well when I wrote it. > > *command line for issue #2:* > morr@redwood ~/mwait-patch/gem5 $ ./build/X86/gem5.debug > --debug-flags=Mwait ./configs/example/se.py -c tests/test-progs/mwait/mwait > -n 2 --cpu-type detailed --ruby > gem5 Simulator System. http://gem5.org > gem5 is copyrighted software; use the --copyright option for details. > > gem5 compiled Jan 23 2013 10:16:52 > gem5 started Feb 16 2013 12:34:37 > gem5 executing on redwood > command line: ./build/X86/gem5.debug --debug-flags=Mwait > ./configs/example/se.py -c tests/test-progs/mwait/mwait -n 2 --cpu-type > detailed --ruby > Global frequency set at 1000000000000 ticks per second > warn: CoherentBus system.membus has no snooping ports attached! > 0: system.remote_gdb.listener: listening for remote gdb #0 on port 7000 > 0: system.remote_gdb.listener: listening for remote gdb #1 on port 7001 > **** REAL SIMULATION **** > info: Entering event queue @ 0. Starting simulation... > warn: instruction 'fldcw_Mw' unimplemented > info: Increasing stack size by one page. > ... > ... > info: Increasing stack size by one page. > fatal: Over max stack size for one thread > @ cycle 10226500 > [fixupStackFault:build/X86/sim/process.cc, line 353] > Memory Usage: 645124 KBytes > > *hack for issue #2:* > morr@redwood ~/mwait-patch/gem5 $ hg diff > diff --git a/configs/example/se.py b/configs/example/se.py > --- a/configs/example/se.py > +++ b/configs/example/se.py > @@ -82,7 +82,7 @@ > > idx = 0 > for wrkld in workloads: > - process = LiveProcess() > + process = LiveProcess(max_stack_size='0B') > process.executable = wrkld > > if len(pargs) > idx: > > Thanks, > Marc > _______________________________________________ > gem5-dev mailing list > gem5-dev@gem5.org > http://m5sim.org/mailman/listinfo/gem5-dev > -- Joel Hestness PhD Student, Computer Architecture Dept. of Computer Science, University of Wisconsin - Madison http://pages.cs.wisc.edu/~hestness/ _______________________________________________ gem5-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev
