Messages in this thread | | | Subject | Re: [RFC][PATCH 00/11] perf pmu interface -v2 | From | Will Deacon <> | Date | Fri, 02 Jul 2010 13:55:38 +0100 |
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Hi Peter,
On Thu, 2010-07-01 at 15:36 +0100, Peter Zijlstra wrote: > On Fri, 2010-06-25 at 16:50 +0200, Peter Zijlstra wrote: > > > Not exactly sure how I could have messed up the ARM architecture code to > > make this happen though... will have a peek. > > I did find a bug in there, not sure it could have been responsible for > this but who knows... > > Pushed out a new git tree with the below delta folded in. > I had a look at this yesterday and discovered a bug in the ARM backend code, which I've posted a patch for to ALKML:
http://lists.infradead.org/pipermail/linux-arm-kernel/2010-July/019461.html
Unfortunately, with this applied and your latest changes I still get 0 from pinned hardware counters:
# perf stat -r 5 -e cycles -e instructions -e cs -e faults -e branches -a -- git status
Performance counter stats for 'git status' (5 runs):
0 cycles ( +- nan% ) 0 instructions # 0.000 IPC ( +- nan% ) 88447 context-switches ( +- 12.624% ) 13647 page-faults ( +- 0.015% ) 0 branches ( +- nan% )
The changes you've made to arch/arm/kernel/perf_event.c look sane. If I get some time I'll try and dig deeper.
Will
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