On Sun, 2008-12-28 at 03:45 +0300, malc wrote:

On Thu, 25 Dec 2008, Benjamin Herrenschmidt wrote:

quoted

On Wed, 2008-12-24 at 03:08 +0300, malc@pulsesoft.com wrote:

quoted

Ken Moffat [off-list ref] writes:

quoted

On Tue, Dec 23, 2008 at 06:04:45AM +0300, malc@pulsesoft.com wrote:

[..snip..]

quoted

quoted

Thanks for the reference, but i'm sure, now more than ever, that bad
memory has nothing to do with it, all signs are there that kernel is
confused by the way signals are (mis)used by Mono.

It shouldn't be but I agree with you, it smells bad. Can you report that
again on the linuxppc-dev@ozlabs.org mailing list ? Along with
instructions to d/l, install & run the minimum repro-case ? I'll try to
give it a go on different ppc64 machines as soon as I'm over my upcoming
xmas hangover :-) If it appears to be ps3 specific, we can work with
Geoff Levand (PS3 maintainer for Sony) to try to identify the root cause
and fix it.

I've posted a message to linuxppc-dev via gmane, but AFAICS it never made
it there. Anyhow, here's another try:

Mono can be obtained from:
http://ftp.novell.com/pub/mono/sources/mono/mono-2.0.1.tar.bz2

Although 2.0.1 only supports ppc32 the problem is still reproducible.

Now to the Christmas cheer, i've tried v2.6.28 and couldn't help but
notice that the problem is gone, bisecting v2.6.27 (which funnily i
had to mark good) to v2.6.28 (which has to be marked bad) wasn't fun
but eventually converged at ab598b6680f1e74c267d1547ee352f3e1e530f89

commit ab598b6680f1e74c267d1547ee352f3e1e530f89
Author: Paul Mackerras [off-list ref]
Date:   Sun Nov 30 11:49:45 2008 +0000

     powerpc: Fix system calls on Cell entered with XER.SO=1

Now the lock-up is gone, however the code never exercises the path
taken during the lock-up so i guess it, at least, deserves a better
look by PPC64 care takers.

I'm confused. Which code never exercises which path, and so what
deserves a better look?

AFAICT this fix will help you, and could explain your problem. You're on
Cell, so you're using the mftb workaround, and ps3_defconfig has
CONFIG_VIRT_CPU_ACCOUNTING=y.

cheers

-- 
Michael Ellerman
OzLabs, IBM Australia Development Lab

wwweb: http://michael.ellerman.id.au
phone: +61 2 6212 1183 (tie line 70 21183)

We do not inherit the earth from our ancestors,
we borrow it from our children. - S.M.A.R.T Person