Re: [Qemu-devel] [PATCH 5/9] virtio-blk: multiqueue batch notify

[Stefan Hajnoczi <stefanha@gmail.com>]

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On Sat, May 21, 2016 at 06:02:52PM +0200, Paolo Bonzini wrote:
> 
> 
> On 21/05/2016 01:40, Stefan Hajnoczi wrote:
> > +    while ((i = find_next_bit(s->batch_notify_vqs, nvqs, i)) < nvqs) {
> > +        VirtQueue *vq = virtio_get_queue(vdev, i);
> > +
> > +        bitmap_clear(s->batch_notify_vqs, i, 1);
> 
> clear_bit?

Ignorance on my part.  Thanks!

> > +        if (s->dataplane_started && !s->dataplane_disabled) {
> > +            virtio_blk_data_plane_notify(s->dataplane, vq);
> > +        } else {
> > +            virtio_notify(vdev, vq);
> > +        }
> 
> The find_next_bit loop is not very efficient and could use something
> similar to commit 41074f3 ("omap_intc: convert ffs(3) to ctz32() in
> omap_inth_sir_update()", 2015-04-28).  But it can be improved later.

Cool, will try that for inspiration in v2.

Stefan

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