On Tue, Jun 28, 2022 at 6:01 AM Jason Wang <jasow...@redhat.com> wrote:
>
> On Thu, Jun 23, 2022 at 4:58 PM Stefano Garzarella <sgarz...@redhat.com>
> wrote:
> >
> > On Thu, Jun 23, 2022 at 11:50:22AM +0800, Jason Wang wrote:
> > >On Wed, Jun 22, 2022 at 12:09 AM Stefano Garzarella <sgarz...@redhat.com>
> > >wrote:
> > >>
> > >> Limit the number of requests (4 per queue as for vdpa_sim_net) handled
> > >> in a batch to prevent the worker from using the CPU for too long.
> > >>
> > >> Suggested-by: Eugenio Pérez <epere...@redhat.com>
> > >> Signed-off-by: Stefano Garzarella <sgarz...@redhat.com>
> > >> ---
> > >> drivers/vdpa/vdpa_sim/vdpa_sim_blk.c | 15 ++++++++++++++-
> > >> 1 file changed, 14 insertions(+), 1 deletion(-)
> > >>
> > >> diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
> > >> b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
> > >> index a83a5c76f620..ac86478845b6 100644
> > >> --- a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
> > >> +++ b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c
> > >> @@ -197,6 +197,7 @@ static bool vdpasim_blk_handle_req(struct vdpasim
> > >> *vdpasim,
> > >> static void vdpasim_blk_work(struct work_struct *work)
> > >> {
> > >> struct vdpasim *vdpasim = container_of(work, struct vdpasim,
> > >> work);
> > >> + bool reschedule = false;
> > >> int i;
> > >>
> > >> spin_lock(&vdpasim->lock);
> > >> @@ -206,11 +207,15 @@ static void vdpasim_blk_work(struct work_struct
> > >> *work)
> > >>
> > >> for (i = 0; i < VDPASIM_BLK_VQ_NUM; i++) {
> > >> struct vdpasim_virtqueue *vq = &vdpasim->vqs[i];
> > >> + bool vq_work = true;
> > >> + int reqs = 0;
> > >>
> > >> if (!vq->ready)
> > >> continue;
> > >>
> > >> - while (vdpasim_blk_handle_req(vdpasim, vq)) {
> > >> + while (vq_work) {
> > >> + vq_work = vdpasim_blk_handle_req(vdpasim, vq);
> > >> +
> > >
> > >Is it better to check and exit the loop early here?
> >
> > Maybe, but I'm not sure.
> >
> > In vdpa_sim_net we call vringh_complete_iotlb() and send notification
> > also in the error path,
>
> Looks not?
>
> read = vringh_iov_pull_iotlb(&cvq->vring, &cvq->in_iov, &ctrl,
> sizeof(ctrl));
> if (read != sizeof(ctrl))
> break;
>
> We break the loop.
I was looking at vdpasim_net_work(), but I was confused since it
handles 2 queues.
I'll break the loop as it was before.
Thanks,
Stefano
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