Messages in this thread Patch in this message | | | Date | Wed, 25 Nov 2009 10:43:38 +0100 | From | Ingo Molnar <> | Subject | Re: [RFC][PATCH 0/7] perf trace: general-purpose scripting support, v2 |
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* Peter Zijlstra <peterz@infradead.org> wrote:
> On Wed, 2009-11-25 at 09:28 +0100, Peter Zijlstra wrote: > > On Wed, 2009-11-25 at 01:15 -0600, Tom Zanussi wrote: > > > sched::sched_wakeup 0 01238.657997033 6183 firefox comm=firefox, pid=6199, prio=120, success=1, target_cpu=1 > > > sched::sched_switch 1 01238.657991740 7140 firefox prev_comm=firefox, prev_pid=7140, prev_prio=120, prev_state=S, next_comm=firefox, next_pid=6199, next_prio=120 > > > > > > min_wakeup_latency: -5293 > > > > Looks like we missed a clock update on the cross cpu wakeup, Mike was > > busy plugging those holes -- I've been starting at a patch that might > > cure this (amongst other things). > > Hmm, current -tip should have that cured as per:
well, but timestamp inconsistencies are still possible fundamentally, as cpu_clock() is not globally serialized.
If so then the (hack only) patch below would cure those timestamp inconsistencies?
Ingo
Not-Signed-off-by-me
diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 35df94e..4f36b47 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -248,7 +248,7 @@ static void perf_unpin_context(struct perf_event_context *ctx) static inline u64 perf_clock(void) { - return cpu_clock(smp_processor_id()); + return trace_clock_global(); } /*
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