From: Dimitri Sivanich <sivanich@sgi.com>
To: Peter Zijlstra <peterz@infradead.org>,
linux-kernel@vger.kernel.org, tony.luck@intel.com
Cc: Ingo Molnar <mingo@elte.hu>, Mike Galbraith <efault@gmx.de>,
Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
Gregory Haskins <ghaskins@novell.com>, Greg KH <greg@kroah.com>,
Nick Piggin <npiggin@suse.de>, Robin Holt <holt@sgi.com>
Subject: Re: 2.6.27.8 scheduler bug - threads not being scheduled for long periods
Date: Mon, 5 Jan 2009 17:02:18 -0600 [thread overview]
Message-ID: <20090105230218.GC20319@sgi.com> (raw)
In-Reply-To: <20090105223621.GB20319@sgi.com>
Peter,
On Mon, Jan 05, 2009 at 04:36:21PM -0600, Dimitri Sivanich wrote:
> And sure enough, the rq->clock is sometimes going backwards.
>
> The comment for sched_clock() in arch/ia64/kernel/head.S:
> * Return a CPU-local timestamp in nano-seconds. This timestamp is
> * NOT synchronized across CPUs its return value must never be
> * compared against the values returned on another CPU. The usage in
> * kernel/sched.c ensures that.
>
> We will try this with CONFIG_HAVE_UNSTABLE_SCHED_CLOCKS.
>
The testcase does indeed run with CONFIG_HAVE_UNSTABLE_SCHED_CLOCKS configured.
next prev parent reply other threads:[~2009-01-05 23:02 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-05 17:56 2.6.27.8 scheduler bug - threads not being scheduled for long periods Dimitri Sivanich
2009-01-05 18:44 ` Gregory Haskins
2009-01-05 18:51 ` Dimitri Sivanich
2009-01-05 18:59 ` Gregory Haskins
2009-01-14 22:34 ` kenneth johansson
2009-01-05 20:55 ` Peter Zijlstra
2009-01-05 21:54 ` Dimitri Sivanich
2009-01-05 22:36 ` Dimitri Sivanich
2009-01-05 23:02 ` Dimitri Sivanich [this message]
2009-01-06 7:36 ` Peter Zijlstra
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