Re: KVM induced panic on 2.6.38[2367] & 2.6.39

From: Avi Kivity
Date: Wed Jun 01 2011 - 02:57:05 EST

On 06/01/2011 09:31 AM, Brad Campbell wrote:
On 01/06/11 12:52, Hugh Dickins wrote:

I guess Brad could try SLUB debugging, boot with slub_debug=P
for poisoning perhaps; though it might upset alignments and
drive the problem underground. Or see if the same happens
with SLAB instead of SLUB.

Not much use I'm afraid.
This is all I get in the log

[ 3161.300073] =============================================================================
[ 3161.300147] BUG kmalloc-512: Freechain corrupt

The qemu process is then frozen, unkillable but reported in state "R"

13881 ? R 3:27 /usr/bin/qemu -S -M pc-0.13 -enable-kvm -m 1024 -smp 2,sockets=2,cores=1,threads=1 -nam

The machine then progressively dies until it's frozen solid with no further error messages.

I stupidly forgot to do an alt-sysrq-t prior to doing an alt-sysrq-b, but at least it responded to that.

On the bright side I can reproduce it at will.

Please try slub_debug=FZPU; that should point the finger (hopefully at somebody else).

I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.

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