Re: CONFIG_PREEMPT causes corruption of application's FPU stack

From: Steven Rostedt
Date: Sun May 18 2008 - 11:08:18 EST

On Sat, May 17, 2008 at 06:31:08PM +0200, J?rgen Mell wrote:
> I tracked this down to a single kernel configuration option. If
> CONFIG_PREEMPT is set to 'y' the application will start crashing. If
> CONFIG_PREEMPT is replaced by CONFIG_PREEMPT_VOLUNTARY, the application
> will run without errors.
> The problem is reproducible in so far as the error always occurs when
> CONFIG_PREEMPT is set, but the time to the first occurrence varies greatly
> from some minutes up to more than 10 CPU hours.
> I found this error first on an openSUSE kernel I verified
> the problem on the following kernel versions:
> openSUSE
> openSUSE
> 2.6.26-rc1
> 2.6.26-rc2-git5

So you see this error in both the SuSE RT kernel, *and* mainline

If you see it in the kernel, can you please do a git-bisect
to see which commit caused the problem?


-- Steve

> My CPU is an Intel Core2Duo 6420, running two of the Einstein applications
> in 32-bit mode. From a discussion on the Einstein message boards I know
> that other user of the application are also affected.
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