[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] KVM brokenness due to IO thread changes

From: Jan Kiszka
Subject: Re: [Qemu-devel] KVM brokenness due to IO thread changes
Date: Tue, 28 Apr 2009 21:56:23 +0200
User-agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv: Gecko/20080226 SUSE/ Thunderbird/ Mnenhy/

Marcelo Tosatti wrote:
> Jan,
> On Tue, Apr 28, 2009 at 09:40:01AM +0200, Jan Kiszka wrote:
>> Hi,
>> this is a heads-up, maybe someone has some time to look into this over
>> the day: I seems like the IO thread changes caused a few regressions to
>> the KVM mode.
>> When I keep this feature disabled, I see strange hick-ups of the event
>> delivery mechanism, and the guest stops once in a while for a second or
>> so. Attaching strace makes the whole process terminate early (looks like
>> it triggers a race in the signal handling). And when I enable the IO
>> thread, I immediately get a deadlock on qemu_global_mutex.
> Yes its borked. The iothread should signal the vcpu thread whenever it
> wants to grab the mutex lock, because unlike kvm-userspace it does not
> drop the global mutex when entering guest mode (VCPU_RUN ioctl).
> Anthony will commit patches to fix that soon.

Looking forward. It's far more efficient to test my infrastructure
changes against the KVM mode.

>> Moreover:
>>   CC    i386-softmmu/vl.o
>> /data/qemu/vl.c:4380: warning: ‘qemu_calculate_timeout’ defined but not used
>> Jan
> BTW, can you please review the changes made to the debugging logic in
> the main loop sometime? (there's a debug_requested global now).

Looks OK and works fine.


Attachment: signature.asc
Description: OpenPGP digital signature

reply via email to

[Prev in Thread] Current Thread [Next in Thread]