[Qemu-devel] Re: [PATCH] qemu: work around for "posix-aio-compat"

[Michael S. Tsirkin]

On Tue, Oct 20, 2009 at 08:57:13PM +0200, Paolo Bonzini wrote:
> On 10/20/2009 08:39 PM, Mark McLoughlin wrote:
>> On Thu, 2009-10-08 at 22:37 +0200, Michael S. Tsirkin wrote:
>>> With commit ee3993069ff55fa6f1c64daf1e09963e340db8e4,
>>> "posix-aio-compat: avoid signal race when spawning a thread"
>>> winxp installation on a raw format file fails
>>> during disk format, with a message "your
>>> disk may be damaged".
>>>
>>> This commit moved signal mask from aio thread to creating thread.
>>> It turns out if we keep the mask in aio thread as well, the problem
>>> disappears. It should not be needed, but since this is harmless, let's
>>> keep it around until someone inclined to debug pthread library internals
>>> can check this issue.
>>>
>>> While we are at it, convert sigprocmask to pthread_sigmask
>>> as per posix.
>>
>> FWIW, I just started hitting a boot hang with qemu.git and --enable-kvm
>> on a Fedora 11 machine with a Fedora 11 guest.
>>
>> I bisected it back to malc's commit, found this thread, applied
>> Michael's patch and confirmed that it fixes the problem for me too.
>
> If anybody can send me the output of compiling the "strange" file with  
> and without the patch, both with "-fdump-tree-all -fdump-rtl-all -O2  
> --save-temps -g" flags, I could try debugging it in GCC.
>
> It will be huge, so bz/gz/lzip it.

I've uploaded them here:
http://www.kernel.org/pub/linux/kernel/people/mst/
you can't see them in mirrors yet but will be able to soon when
kernel.org mirroring system catches them.


> Paolo