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Date: Tue, 20 Sep 2011 16:48:21 +0200
From: Gerd Hoffmann <kraxel@redhat.com>
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Subject: Re: [Qemu-devel] qxl: pthread_yield on QXL_IO_NOTIFY_OOM
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To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: qemu-devel <qemu-devel@nongnu.org>

On 09/20/11 16:27, Jan Kiszka wrote:
> Hi Gerd,
>
> can you (or anyone familiar with those bits) comment on pthread_yield()
> in ioport_write() of hw/qxl.c?  Which threads are supposed to run this
> way?

spice server thread.

> Can't this relation be expressed explicitly?

The thread is created by libspice-server, so we don't have a handle for it.

> If not, can we use a
> sleep here (how long?)?

Good question.  I'm tempted to just rip it out and run qxl_spice_oom() 
unconditionally.  The yield thing is best effort only anyway, there is 
no guarantee that the spice server thread actually gets scheduled and 
puts some stuff into the release ring.

cheers,
   Gerd