Messages in this thread | | | Date | Mon, 25 Jan 2010 10:04:43 -0800 | From | Greg KH <> | Subject | Re: [Stable-review] [28/29] perf events: Dont report side-band events on each cpu for per-task-per-cpu events |
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On Sat, Jan 23, 2010 at 12:38:41PM +0100, Stefan Bader wrote: > Greg KH wrote: > > 2.6.32-stable review patch. If anyone has any objections, please let us know. > > > > ------------------ > > > > From: Peter Zijlstra <a.p.zijlstra@chello.nl> > > > > commit 5d27c23df09b702868d9a3bff86ec6abd22963ac upstream. > > > > Acme noticed that his FORK/MMAP numbers were inflated by about > > the same factor as his cpu-count. > > > > This led to the discovery of a few more sites that need to > > respect the event->cpu filter. > > > > Reported-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> > > Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> > > Cc: Paul Mackerras <paulus@samba.org> > > LKML-Reference: <20091217121830.215333434@chello.nl> > > Signed-off-by: Ingo Molnar <mingo@elte.hu> > > Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> > > > > --- > > kernel/perf_event.c | 20 ++++++++++++++++++-- > > 1 file changed, 18 insertions(+), 2 deletions(-) > > > > --- a/kernel/perf_event.c > > +++ b/kernel/perf_event.c > > @@ -1359,6 +1359,9 @@ static void perf_ctx_adjust_freq(struct > > if (event->state != PERF_EVENT_STATE_ACTIVE) > > continue; > > > > + if (event->cpu != -1 && event->cpu != smp_processor_id()) > > + continue; > > + > > hwc = &event->hw; > > > > interrupts = hwc->interrupts; > > @@ -3226,6 +3229,9 @@ static void perf_event_task_output(struc > > > > static int perf_event_task_match(struct perf_event *event) > > { > > + if (event->cpu != -1 && event->cpu != smp_processor_id()) > > + return 0; > > + > > if (event->attr.comm || event->attr.mmap || event->attr.task) > > return 1; > > > > > @@ -3262,6 +3268,7 @@ static void perf_event_task_event(struct > > ctx = rcu_dereference(task_event->task->perf_event_ctxp); > > if (ctx) > > perf_event_task_ctx(ctx, task_event); > > + put_cpu_var(perf_cpu_context); > > rcu_read_unlock(); > > } > > I believe this hunk drops the move of put_cpu_var. The upstream hunk looks like > this: > > @ -3290,12 +3296,11 @@ static void perf_event_task_event(struct perf_task_event > rcu_read_lock(); > cpuctx = &get_cpu_var(perf_cpu_context); > perf_event_task_ctx(&cpuctx->ctx, task_event); > - put_cpu_var(perf_cpu_context); > - > if (!ctx) > ctx = rcu_dereference(task_event->task->perf_event_ctxp); > if (ctx) > perf_event_task_ctx(ctx, task_event); > + put_cpu_var(perf_cpu_context); > rcu_read_unlock(); > }
All fixed up now, thanks again for the review.
greg k-h
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