Re: What exactly are the issues with 2.6.0-test10 preempt?

Bradley Chapman
2003-11-24T21:29:53Z

Mr. Liakhovetski,

--- Guennadi Liakhovetski <g.liakhovetski@gmx.de> wrote:
> On Mon, 24 Nov 2003, Bradley Chapman wrote:
>
> > I saw in Linus' 2.6.0-test10 announcement that preempt is suffering from some
> > problems and should not be used. However, I am currently running 2.6.0-test10
> > with CONFIG_PREEMPT=y and nothing has appeared yet. To see if the problem
> appeared
> > under stress, I started an A/V trailer playback with mplayer and then ran the
> > find command on both my home directory and the 2.6.0-test10 kernel source
> directory,
> > with the expected result - mplayer did not skip, neither find invocation broke,
> > and there were no nasty errors in dmesg.
> >
> > So what exactly is the problem?
>
> Well, FWIW, I'm getting 100% reproducible Oopses on __boot__ by enabling
> preemption AND (almost) all kernel-hacking CONFIG_DEBUG_* options - see my
> post of 21.11.2003 with subject "[OOPS] 2.6.0-test7 + preempt + hacking".
> If required, could try to narrow it down to 1 CONFIG option. However, the
> Oops itself happens somewhere in NFS code (see backtrace in above email
> for details).

Hmmm. This is what I have enabled under "Kernel hacking":

#
# Kernel hacking
#
CONFIG_DEBUG_KERNEL=y
CONFIG_DEBUG_STACKOVERFLOW=y
CONFIG_DEBUG_SLAB=y
CONFIG_DEBUG_IOVIRT=y
CONFIG_MAGIC_SYSRQ=y
CONFIG_DEBUG_SPINLOCK=y
# CONFIG_DEBUG_PAGEALLOC is not set
# CONFIG_DEBUG_INFO is not set
CONFIG_DEBUG_SPINLOCK_SLEEP=y
# CONFIG_FRAME_POINTER is not set
CONFIG_X86_EXTRA_IRQS=y
CONFIG_X86_FIND_SMP_CONFIG=y
CONFIG_X86_MPPARSE=y

So far, though, not a single problem -- I was playing Flash animations while
printing a huge document without a single hiccup (I have an HP DeskJet 880C with
very little memory, so there was a lot of in-kernel activity).

>
> Guennadi

Brad

=====

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