From: compudj@krystal.dyndns.org (Mathieu Desnoyers)
Subject: [ltt-dev] trace a futex
Date: Fri, 5 Dec 2008 07:28:22 -0500 [thread overview]
Message-ID: <20081205122822.GA25816@Krystal> (raw)
In-Reply-To: <1228380784.5092.18.camel@twins>
* Peter Zijlstra (peterz at infradead.org) wrote:
>
> FWIW, the ftrace infrastructure has on many an occasion (even before it
> was called ftrace and specific to -rt) helped in debugging and fixing
> futex races.
>
Hrm, I'm not sure futex races is the key aspect of interest here.
Knowing which amount of pthread mutex lock calls ends up calling the
scheduler looks a bit more like the topic brought by this particular
use-case. Therefore, correlating the information from the nptl with the
kernel information would be useful.
Is lockdep called when a futex is taken ? Should we add instrumentation
(tracepoints) to futex.c ? If yes, was there specific instrumentation
you used with ftrace that should be added ?
Mathieu
--
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
next prev parent reply other threads:[~2008-12-05 12:28 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-12-02 19:42 Gian Lorenzo Meocci
2008-12-02 19:50 ` Mathieu Desnoyers
2008-12-02 20:15 ` Gian Lorenzo Meocci
2008-12-02 21:55 ` Mathieu Desnoyers
2008-12-02 22:10 ` Jan Kiszka
2008-12-02 22:10 ` Jan Kiszka
2008-12-02 22:10 ` Jan Kiszka
2008-12-03 5:26 ` Mathieu Desnoyers
2008-12-03 5:26 ` Mathieu Desnoyers
2008-12-03 5:26 ` Mathieu Desnoyers
2008-12-03 18:01 ` K.Prasad
2008-12-04 8:53 ` Peter Zijlstra
2008-12-05 12:28 ` Mathieu Desnoyers [this message]
2008-12-05 15:58 ` Peter Zijlstra
2008-12-05 16:01 ` Peter Zijlstra
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