From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@ghostprotocols.net>,
linux-kernel@vger.kernel.org
Subject: Re: Perf events warning..
Date: Tue, 15 May 2012 12:49:56 +0200 [thread overview]
Message-ID: <1337078996.27694.26.camel@twins> (raw)
In-Reply-To: <CA+55aFxHw_SOX7fvcwskwP0qvLwyeXxTFjk589pnQtmYevhvpw@mail.gmail.com>
On Mon, 2012-05-14 at 15:25 -0700, Linus Torvalds wrote:
> On Mon, May 14, 2012 at 3:20 PM, Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:
> >
> > So far I can't make any of the things I came up stick. You ran something
> > simple like: 'perf record -e cycles:pp -F 20000 make test' ? Or did you
> > do something more interesting?
>
> It was not much more complex than that.
>
> It did use "make -j64 test" to make the load a *bit* more interesting
> (and go noticeably faster), but other than that you got it.
OK, that limits the scope of crazy scenarios I have to consider, still
no immediate clue though..
I think I've found a possible race, but I can't make it work with that
workload. I've also let your workload run for 2+ hours in trying to
reproduce, but no luck, it must be a very narrow window indeed.
I'll keep prodding at it..
next prev parent reply other threads:[~2012-05-15 10:50 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-11 15:43 Perf events warning Linus Torvalds
2012-05-14 22:20 ` Peter Zijlstra
2012-05-14 22:25 ` David Ahern
2012-05-14 22:25 ` Linus Torvalds
2012-05-15 10:49 ` Peter Zijlstra [this message]
2012-05-15 15:25 ` David Ahern
2012-05-15 15:28 ` Peter Zijlstra
2012-05-15 15:37 ` David Ahern
2012-05-16 1:38 ` Namhyung Kim
2012-05-21 6:06 ` Namhyung Kim
2012-05-15 15:46 ` Arnaldo Carvalho de Melo
2012-05-15 15:48 ` Linus Torvalds
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