From: Peter Zijlstra <peterz@infradead.org>
To: Valdis.Kletnieks@vt.edu
Cc: Andrew Morton <akpm@linux-foundation.org>,
Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
linux-kernel@vger.kernel.org
Subject: Re: Stupid futex question - 2.6.33-rc7-mmotm0210
Date: Thu, 18 Feb 2010 18:01:26 +0100 [thread overview]
Message-ID: <1266512486.26719.856.camel@laptop> (raw)
In-Reply-To: <7380.1266511335@localhost>
On Thu, 2010-02-18 at 11:42 -0500, Valdis.Kletnieks@vt.edu wrote:
> 1) should it get killed for RLIMIT_RTTIME because it's been in a futex()
> for multiple seconds? It seems suspicious - docs say a blocking syscall
> resets RTTIME - so if futex() blocks it shouldn't kill, and if it's in the
> kernel for a second without blocking it's a bug too.
sys_futex() shouldn't be taking that long indeed, and if its not caused
by the sysrq interrupt then something funny is going on indeed.
You could poke around in kernel/futex.c:futex_wait() to see where it
thinks its spending it time? There's a single retry loop in there, maybe
instrument that to see if its retrying too many times..
next prev parent reply other threads:[~2010-02-18 17:01 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-18 14:04 Stupid futex question - 2.6.33-rc7-mmotm0210 Valdis.Kletnieks
2010-02-18 14:37 ` Peter Zijlstra
2010-02-18 16:42 ` Valdis.Kletnieks
2010-02-18 17:01 ` Peter Zijlstra [this message]
2010-02-18 18:45 ` Thomas Gleixner
2010-02-19 4:08 ` Darren Hart
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