Re: [PATCH v2 2/3] vdpa_sim_blk: limit the number of request handled per batch
From: Jason Wang <hidden>
Date: 2022-07-05 03:11:51
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On Thu, Jun 30, 2022 at 11:32 PM Stefano Garzarella [off-list ref] 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 <eperezma@redhat.com> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Jason Wang <redacted>
quoted hunk ↗ jump to hunk
--- v2: - restored previous behaviour, exiting the loop immediately if the request is malformed [Jason] --- drivers/vdpa/vdpa_sim/vdpa_sim_blk.c | 10 ++++++++++ 1 file changed, 10 insertions(+)diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c b/drivers/vdpa/vdpa_sim/vdpa_sim_blk.c index a83a5c76f620..b2d75efec63a 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);@@ -206,6 +207,7 @@ 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]; + int reqs = 0; if (!vq->ready) continue;@@ -218,10 +220,18 @@ static void vdpasim_blk_work(struct work_struct *work) if (vringh_need_notify_iotlb(&vq->vring) > 0) vringh_notify(&vq->vring); local_bh_enable(); + + if (++reqs > 4) { + reschedule = true; + break; + } } } out: spin_unlock(&vdpasim->lock); + + if (reschedule) + schedule_work(&vdpasim->work); } static void vdpasim_blk_get_config(struct vdpasim *vdpasim, void *config) --2.36.1
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