Re: [patch] perf wrong enabled time after attach/enable/enable

From	Peter Zijlstra <peterz@infradead.org>
Newsgroups	linux.kernel
Subject	Re: [patch] perf wrong enabled time after attach/enable/enable
Date	2017-08-09 18:40 +0200
Message-ID	<ucCbw-1mZ-15@gated-at.bofh.it> (permalink)
References	<u7jCx-2ek-7@gated-at.bofh.it> <ua5tn-4lS-1@gated-at.bofh.it> <uasJj-3EH-11@gated-at.bofh.it> <uaIXL-6k3-1@gated-at.bofh.it>
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On Fri, Aug 04, 2017 at 01:22:53PM +0200, Peter Zijlstra wrote:
> On Thu, Aug 03, 2017 at 02:07:53PM -0400, Vince Weaver wrote:
> > On Wed, 2 Aug 2017, Peter Zijlstra wrote:
> > 
> > > Playing with that test it really is the IOC_DISABLE while STOP'ed that
> > > messes things up.
> > > 
> > > Ah.. magic.. the below seems to fix things, hopefully it doesn't break
> > > anything else.
> > 
> > yes, I've tested this and it seems to fix things.
> 
> New version below.. is a bit different and should handle another case.
> I'll try and run more tests on it, because while it _SHOULD_ not trigger
> that WARN_ON_ONCE() you know how that goes..

And splat it goes.. turns out we can attach to a ctx when OFF (which
makes sense, they need to live someplace too).

In that case the IOC_ENABLE will again go through
__perf_event_enable_time() and recompute things.

I think I'll just remove the WARN_ON_ONCE(), and put in a comment.

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Re: [patch] perf wrong enabled time after attach/enable/enable Peter Zijlstra <peterz@infradead.org> - 2017-08-02 19:20 +0200
  Re: [patch] perf wrong enabled time after attach/enable/enable Vince Weaver <vincent.weaver@maine.edu> - 2017-08-03 20:10 +0200
    Re: [patch] perf wrong enabled time after attach/enable/enable Peter Zijlstra <peterz@infradead.org> - 2017-08-04 13:30 +0200
      Re: [patch] perf wrong enabled time after attach/enable/enable Vince Weaver <vincent.weaver@maine.edu> - 2017-08-04 15:40 +0200
      Re: [patch] perf wrong enabled time after attach/enable/enable Peter Zijlstra <peterz@infradead.org> - 2017-08-09 18:40 +0200

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