Re: [PATCH] perf/x86: Reject non sampling events with precise_ip

From	Vince Weaver <vince@deater.net>
Newsgroups	linux.kernel
Subject	Re: [PATCH] perf/x86: Reject non sampling events with precise_ip
Date	2017-01-03 23:10 +0100
Message-ID	<sVFrk-48v-35@gated-at.bofh.it> (permalink)
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On Tue, 3 Jan 2017, Jiri Olsa wrote:
> On Tue, Jan 03, 2017 at 10:40:59AM +0100, Peter Zijlstra wrote:
> > 
> > I think we should reject non sampling pebs events, as you say they make
> > no sense what so ever.
> 
> ook, attached
> 

you can use the PEBS events to gather aggregate stats though and they 
seem roughly right.  Are they truly meaningless?

I had misremembered that they might not have the determinism problems of 
regular events (turns out that's wrong).  They oddly seem to be worse in 
some limited tests I did.

So I guess nothing will be lost if they're disabled.

Vince

Thread

[PATCH 2/4] perf/x86: Fix period for non sampling events Jiri Olsa <jolsa@kernel.org> - 2016-12-28 14:40 +0100
  Re: [PATCH 2/4] perf/x86: Fix period for non sampling events Peter Zijlstra <peterz@infradead.org> - 2017-01-03 10:50 +0100
    [PATCH] perf/x86: Reject non sampling events with precise_ip Jiri Olsa <jolsa@redhat.com> - 2017-01-03 15:30 +0100
      Re: [PATCH] perf/x86: Reject non sampling events with precise_ip Vince Weaver <vince@deater.net> - 2017-01-03 23:10 +0100
      [tip:perf/urgent] perf/x86: Reject non sampling events with  precise_ip tip-bot for Jiri Olsa <tipbot@zytor.com> - 2017-01-14 13:40 +0100
  Re: [PATCH 2/4] perf/x86: Fix period for non sampling events Peter Zijlstra <peterz@infradead.org> - 2017-01-03 16:20 +0100
    Re: [PATCH 2/4] perf/x86: Fix period for non sampling events Jiri Olsa <jolsa@redhat.com> - 2017-01-03 16:30 +0100

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