From: Ingo Molnar <mingo@elte.hu>
To: Vince Weaver <vweaver1@eecs.utk.edu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
linux-kernel@vger.kernel.org, paulus@samba.org, acme@redhat.com,
torvalds@linux-foundation.org
Subject: Re: perf: definition of a "regression"
Date: Thu, 2 Jun 2011 09:45:30 +0200 [thread overview]
Message-ID: <20110602074530.GF2150@elte.hu> (raw)
In-Reply-To: <alpine.DEB.2.00.1105280918510.27439@cl320.eecs.utk.edu>
* Vince Weaver <vweaver1@eecs.utk.edu> wrote:
> On Sat, 28 May 2011, Peter Zijlstra wrote:
>
> > On Fri, 2011-05-27 at 23:38 -0400, Vince Weaver wrote:
> > > on that note (and while trying to document exactly what the ioctls do) it
> > > seems that a PERF_EVENT_IOC_REFRESH with an argument of anything higher
> > > than one does not work on kernels 2.6.36 and newer. The behavior acts
> > > as if 1 was passed, even if you pass in, say, 3.
> >
> > Urgh, no that should definitely work. Thanks for the test-case, I'll
> > work on that (probably not until Monday though, but who knows).
>
> So wait, the two regressions I found in 2.6.37 are WONTFIX because
> they are too old, even though they break existing userspace code?
>
> And this older regression in 2.6.36 is going to be fixed, even
> though perf, PAPI, and libpfm4 don't trigger the buggy
> functionality at all?
Btw., these considerations are flexible and we can reconsider and
change the WONTFIX if there's a patch available and doesn't look
horrible to backport. We can also mark fixes that havent been marked
-stable originally as -stable later on, etc.
So please don't feel needlessly bitter about past decisions: when
there's some good technical solution to a problem (or we were plain
out wrong about a decision) we try hard not to stand in the way.
Thanks,
Ingo
next prev parent reply other threads:[~2011-06-02 7:45 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-23 20:04 perf: regression with PERF_EVENT_IOC_REFRESH Vince Weaver
2011-05-23 20:22 ` Peter Zijlstra
2011-05-24 6:20 ` Vince Weaver
2011-05-24 10:30 ` Peter Zijlstra
2011-05-24 15:04 ` Vince Weaver
2011-05-24 15:10 ` Peter Zijlstra
2011-05-24 15:40 ` Ingo Molnar
2011-05-24 20:31 ` Vince Weaver
2011-05-25 10:39 ` Ingo Molnar
2011-05-25 21:24 ` Vince Weaver
2011-05-24 17:53 ` Vince Weaver
2011-05-24 15:11 ` Peter Zijlstra
2011-05-24 15:18 ` Peter Zijlstra
2011-05-24 21:48 ` Vince Weaver
2011-05-28 3:38 ` Vince Weaver
2011-05-28 10:22 ` Peter Zijlstra
2011-05-28 13:26 ` perf: definition of a "regression" Vince Weaver
2011-06-02 7:45 ` Ingo Molnar [this message]
2011-05-29 16:54 ` perf: regression with PERF_EVENT_IOC_REFRESH Vince Weaver
2011-05-31 1:33 ` perf: [patch] " Vince Weaver
2011-05-31 7:17 ` Peter Zijlstra
2011-05-31 7:23 ` Peter Zijlstra
2011-05-31 13:49 ` Vince Weaver
2011-05-31 15:52 ` Peter Zijlstra
2011-05-31 16:39 ` Vince Weaver
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