Subject: Re: Kernel locks up after calling kernel_execve()

From: "Gerhard Pircher" <[email-masked]>
Date: Tue, 13 Nov 2007 23:06:55 +0100

-------- Original-Nachricht --------
> Datum: Wed, 14 Nov 2007 08:43:38 +1100
> Von: Benjamin Herrenschmidt <[email-masked]>
> An: Gerhard Pircher <[email-masked]>
> CC: [email-masked]
> Betreff: Re: Kernel locks up after calling kernel_execve()

> Well, at least the above tells is it's not DMA related.
> 
> I don't know of any deeply hidden problem, so you are probably hitting
> something else ... if you have disabled idle, then it may be useful to
> try instrumenting locks or irq enable/disable.
Well, I only disabled power saving with powersave=off. Are there any other
ways to disable idle? What do you mean with instrumenting locks or
irq enable/disable?

> Also, did you try booting with all kernel debug options enabled ?
I compiled in almost all kernel debugging options and booted the kernel
with driver_debug, initcall_debug and debug. I didn't notice any serious
error messages so far. Not sure however, if I missed a debug option.

> Finally, since the problem seem to have started around a specific kernel
> version, can you try to bisect the patch that causes it ?
Hmm, I'm not sure how to do this (only worked on platform code so far).
I guess you think about checking out a kernel version from the git
repository, which doesn't contain the patch for kernel_execve().
I still suspect the kernel_execve() function (which was introduced in
2.6.17) because the kernel locks up after starting the first user program.
AFAIK kernel threads should be running much earlier.

Thanks!

regards,

Gerhard
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