From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Andi Kleen <ak@linux.intel.com>
Cc: kan.liang@linux.intel.com, Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
linux-kernel@vger.kernel.org, bp@alien8.de,
Stephane Eranian <eranian@google.com>
Subject: Re: [PATCH 1/2] perf: Add munmap callback
Date: Wed, 24 Oct 2018 13:32:08 -0300 [thread overview]
Message-ID: <20181024163208.GC15106@kernel.org> (raw)
In-Reply-To: <20181024162334.GG6218@tassilo.jf.intel.com>
Em Wed, Oct 24, 2018 at 09:23:34AM -0700, Andi Kleen escreveu:
> > +void perf_event_munmap(void)
> > +{
> > + struct perf_cpu_context *cpuctx;
> > + unsigned long flags;
> > + struct pmu *pmu;
> > +
> > + local_irq_save(flags);
> > + list_for_each_entry(cpuctx, this_cpu_ptr(&sched_cb_list), sched_cb_entry) {
>
> Would be good have a fast path here that checks for the list being empty
> without disabling the interrupts. munmap can be somewhat hot. I think
> it's ok to make it slower with perf running, but we shouldn't impact
> it without perf.
Right, look at how its counterpart, perf_event_mmap() works:
void perf_event_mmap(struct vm_area_struct *vma)
{
struct perf_mmap_event mmap_event;
if (!atomic_read(&nr_mmap_events))
return;
<SNIP>
}
- Arnaldo
next prev parent reply other threads:[~2018-10-24 16:32 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-24 15:11 [PATCH 1/2] perf: Add munmap callback kan.liang
2018-10-24 15:11 ` [PATCH 2/2] perf/x86/intel: Fix missing physical address in large PEBS kan.liang
2018-10-24 16:23 ` [PATCH 1/2] perf: Add munmap callback Andi Kleen
2018-10-24 16:32 ` Arnaldo Carvalho de Melo [this message]
2018-10-24 18:12 ` Liang, Kan
2018-10-24 18:28 ` Andi Kleen
2018-10-25 0:31 ` Peter Zijlstra
2018-10-24 19:15 ` Arnaldo Carvalho de Melo
2018-10-24 19:30 ` Stephane Eranian
2018-10-25 0:23 ` Peter Zijlstra
2018-10-25 0:25 ` Stephane Eranian
2018-10-25 0:34 ` Peter Zijlstra
2018-10-25 0:44 ` Stephane Eranian
2018-11-01 14:09 ` Liang, Kan
2018-11-05 10:59 ` Stephane Eranian
2018-11-05 15:43 ` Liang, Kan
2018-11-06 15:00 ` Stephane Eranian
2018-11-06 16:47 ` Liang, Kan
2018-10-25 0:29 ` Peter Zijlstra
2018-10-25 14:00 ` Liang, Kan
2018-10-30 12:51 ` Peter Zijlstra
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