Messages in this thread | | | Date | Fri, 01 Apr 2011 15:05:04 +0400 | From | Cyrill Gorcunov <> | Subject | Re: [RFC] [PATCH] perf, x86: Add PERF_COUNT_HW_NMI_WATCHDOG event |
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On 04/01/2011 02:53 PM, Peter Zijlstra wrote: > On Fri, 2011-04-01 at 01:16 +0400, Cyrill Gorcunov wrote: >> Because of Netburst HW restriction we can't move events arbitrary >> between counters and this makes 'perf top' unable to run if nmi-watchdog >> is running (since both uses PERF_COUNT_HW_CPU_CYCLES but such event is >> bound to run on a few counters only). So as a workaround we could count that named >> non-sleeping ticks (as oprofile does) and both perf top and nmi-watchdog would co-exsist >> without conflicts but kernel needs to know about such specifics -- so PERF_COUNT_HW_NMI_WATCHDOG >> event is introduced. This event is an alias of PERF_COUNT_HW_CPU_CYCLES for non-P4 x86 >> architecture so nothing much changed I think. >> >> Please review, I might be missing something. Also comments on idea is quite welcome since >> it touches ABI part. > > >> arch/x86/kernel/cpu/perf_event_amd.c | 1 + >> arch/x86/kernel/cpu/perf_event_intel.c | 1 + >> arch/x86/kernel/cpu/perf_event_p4.c | 15 +++++++++++++++ >> arch/x86/kernel/cpu/perf_event_p6.c | 1 + >> include/linux/perf_event.h | 1 + >> kernel/watchdog.c | 2 +- >> 6 files changed, 20 insertions(+), 1 deletions(-) > > is x86 the only arch using the watchdog things?
Hm, good question. The powerpc, sparc, sh, arm, mips have PERF_COUNT_HW_CPU_CYCLES. Seems I've missed those archs. Thanks Peter, will take a look.
-- Cyrill
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