Re: [Qemu-devel] [PATCH 09/20] mirror: switch mirror_iteration to AIO

[Paolo Bonzini <pbonzini@redhat.com>]

----- Messaggio originale -----
> Da: "Eric Blake" <eblake@redhat.com>
> A: "Paolo Bonzini" <pbonzini@redhat.com>
> Cc: qemu-devel@nongnu.org, kwolf@redhat.com, stefanha@redhat.com, jcody@redhat.com
> Inviato: Venerdì, 14 dicembre 2012 23:11:02
> Oggetto: Re: [PATCH 09/20] mirror: switch mirror_iteration to AIO
> 
> On 12/12/2012 06:46 AM, Paolo Bonzini wrote:
> > There is really no change in the behavior of the job here, since
> > there is still a maximum of one in-flight I/O operation between
> > the source and the target.  However, this patch already introduces
> > the AIO callbacks (which are unmodified in the next patch)
> > and some of the logic to count in-flight operations and only
> > complete the job when there is none.
> > 
> > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> > ---
> >  block/mirror.c | 155
> >  +++++++++++++++++++++++++++++++++++++++++++--------------
> >  trace-events   |   2 +
> >  2 files changed, 119 insertions(+), 38 deletions(-)
> > 
> 
> > @@ -87,31 +143,30 @@ static int coroutine_fn
> > mirror_iteration(MirrorBlockJob *s,
> >  
> >      end = s->common.len >> BDRV_SECTOR_BITS;
> >      nb_sectors = MIN(nb_sectors, end - sector_num);
> > +
> > +    /* Allocate a MirrorOp that is used as an AIO callback.  */
> > +    op = g_slice_new(MirrorOp);
> > +    op->s = s;
> > +    op->iov.iov_base = s->buf;
> > +    op->iov.iov_len  = nb_sectors * 512;
> 
> Why two spaces?

To align the equal signs. :)

Paolo

> I'm not an expert in this area of code, so my review is weak; but I
> didn't spot anything obviously wrong, so feel free to add my:
> 
> Reviewed-by: Eric Blake <eblake@redhat.com>
> 
> --
> Eric Blake   eblake redhat com    +1-919-301-3266
> Libvirt virtualization library http://libvirt.org
> 
>