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Re: [Qemu-devel] [PATCH 0/3] Release SMP restriction on Windows host
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [PATCH 0/3] Release SMP restriction on Windows host |
Date: |
Tue, 09 Apr 2013 18:16:41 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130311 Thunderbird/17.0.4 |
Il 09/04/2013 18:06, Fabien Chouteau ha scritto:
> As I already explained to this mailling list, we (AdaCore) use QEMU to run a
> lot of short executable (~2 secs) on many different targets. In that
> configuration the SMP restriction on Windows (QEMU runs only on 1 core) was
> not
> efficient on our 16 cores servers.
>
> Few months ago I asked on this mailing list if the restriction could be
> removed. There was no clear answer because nobody was able to tell if it would
> work. We decided to give it a try.
>
> During the last months we only found one problem, it was a dead lock between
> the TCG and IO thread, this is fixed by the second patch.
>
> We also found that suspendThread() and resumeThread() were not synchronous on
> SMP systems, so we added a busy loop to wait for effective suspension.
>
> Since then, we run thousands of QEMU on our SMP Windows servers each day
> without any problem. And of course we greatly improve the execution time of
> our
> test-suites.
Awesome! Thanks guys.
Reviewed-by: Paolo Bonzini <address@hidden>
Paolo