Re: [Qemu-devel] [PATCH] posix-aio-compat: fix latency issues

[Avi Kivity]

On 08/12/2011 06:24 AM, Anthony Liguori wrote:
> On 08/08/2011 06:37 AM, Avi Kivity wrote:
> > +static void spawn_thread_bh_fn(void *opaque)
> > +{
> > +    mutex_lock(&lock);
> > +    do_spawn_thread();
> > +    mutex_unlock(&lock);
> > +}
>
> The locking here is odd.  Why not call do_spawn_thread() without the 
> lock, and acquire the lock for the section that needs to hold it?

Just the way the code evolved.  Note that aio_thread() does need to take 
the lock.  However, it is indeed cleaner to take the lock when needed 
rather than drop it when not.

> Otherwise, the logic seems correct to me.
>
> Kevin, could you also take a look at this patch?

Yes please.

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