Re: [RFC][PATCH 00/11] perf pmu interface -v2
From: Peter Zijlstra
Date: Fri Jun 25 2010 - 10:50:37 EST
On Fri, 2010-06-25 at 15:36 +0100, Will Deacon wrote:
> On Fri, 2010-06-25 at 12:16 +0100, Peter Zijlstra wrote:
> > I seem to have lost a refresh before sending the emails, please check:
> > git://git.kernel.org/pub/scm/linux/kernel/git/peterz/linux-2.6-perf.git perf-pmu
> > I pushed out updated patches there.
> Ok, I rebuilt my Kernel and perf tools from that tree and tested it on a
> quad-core ARMv7 board.
Ooh, neat toy ;-)
> Per-task counters appear to work (software and
> hardware) but pinned hardware counters always return 0:
> root@will-lucid-nfs:~# perf stat -a -e cs -e cycles -e instructions -- ls
> linux-2.6 tmp
> Performance counter stats for 'ls':
> 33 context-switches
> 0 cycles
> 0 instructions # 0.000 IPC
> 0.028572009 seconds time elapsed
> It's odd if only ARM is affected in this way. Do pinned events still work
> for other people?
/me goes build that exact tree on his x86_64.. and gets:
# perf stat -a -e cs -e cycles -e instructions -- ls > /dev/null
Performance counter stats for 'ls':
9225808 instructions # 0.370 IPC
0.002389051 seconds time elapsed
Not exactly sure how I could have messed up the ARM architecture code to
make this happen though... will have a peek.
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