| Message ID | 20201221155033.6771-3-joyce.kong@arm.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Delegated to: | Maxime Coquelin |
| Headers | show |
| Series | replace smp barriers in vhost with C11 atomic | expand |
| Context | Check | Description |
|---|---|---|
| ci/checkpatch | success | coding style OK |
On 12/21/20 4:50 PM, Joyce Kong wrote: > Simply replace the rte_smp_mb barriers with SEQ_CST atomic thread fence, > if there is no load/store operations. > > Signed-off-by: Joyce Kong <joyce.kong@arm.com> > Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com> > --- > examples/vhost_blk/vhost_blk.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/examples/vhost_blk/vhost_blk.c b/examples/vhost_blk/vhost_blk.c > index bb293d492..7ea60863d 100644 > --- a/examples/vhost_blk/vhost_blk.c > +++ b/examples/vhost_blk/vhost_blk.c > @@ -86,9 +86,9 @@ enqueue_task(struct vhost_blk_task *task) > */ > used->ring[used->idx & (vq->vring.size - 1)].id = task->req_idx; > used->ring[used->idx & (vq->vring.size - 1)].len = task->data_len; From here > - rte_smp_mb(); > + rte_atomic_thread_fence(__ATOMIC_SEQ_CST); > used->idx++; > - rte_smp_mb(); > + rte_atomic_thread_fence(__ATOMIC_SEQ_CST); to here, couldn't it be replaced with: __atomic_add_fetch(&used->idx, 1, __ATOMIC_RELEASE); ? > rte_vhost_clr_inflight_desc_split(task->ctrlr->vid, > vq->id, used->idx, task->req_idx); > @@ -112,12 +112,12 @@ enqueue_task_packed(struct vhost_blk_task *task) > desc->id = task->buffer_id; > desc->addr = 0; > > - rte_smp_mb(); > + rte_atomic_thread_fence(__ATOMIC_SEQ_CST); > if (vq->used_wrap_counter) > desc->flags |= VIRTQ_DESC_F_AVAIL | VIRTQ_DESC_F_USED; > else > desc->flags &= ~(VIRTQ_DESC_F_AVAIL | VIRTQ_DESC_F_USED); > - rte_smp_mb(); > + rte_atomic_thread_fence(__ATOMIC_SEQ_CST); > > rte_vhost_clr_inflight_desc_packed(task->ctrlr->vid, vq->id, > task->inflight_idx); >
diff --git a/examples/vhost_blk/vhost_blk.c b/examples/vhost_blk/vhost_blk.c index bb293d492..7ea60863d 100644 --- a/examples/vhost_blk/vhost_blk.c +++ b/examples/vhost_blk/vhost_blk.c @@ -86,9 +86,9 @@ enqueue_task(struct vhost_blk_task *task) */ used->ring[used->idx & (vq->vring.size - 1)].id = task->req_idx; used->ring[used->idx & (vq->vring.size - 1)].len = task->data_len; - rte_smp_mb(); + rte_atomic_thread_fence(__ATOMIC_SEQ_CST); used->idx++; - rte_smp_mb(); + rte_atomic_thread_fence(__ATOMIC_SEQ_CST); rte_vhost_clr_inflight_desc_split(task->ctrlr->vid, vq->id, used->idx, task->req_idx); @@ -112,12 +112,12 @@ enqueue_task_packed(struct vhost_blk_task *task) desc->id = task->buffer_id; desc->addr = 0; - rte_smp_mb(); + rte_atomic_thread_fence(__ATOMIC_SEQ_CST); if (vq->used_wrap_counter) desc->flags |= VIRTQ_DESC_F_AVAIL | VIRTQ_DESC_F_USED; else desc->flags &= ~(VIRTQ_DESC_F_AVAIL | VIRTQ_DESC_F_USED); - rte_smp_mb(); + rte_atomic_thread_fence(__ATOMIC_SEQ_CST); rte_vhost_clr_inflight_desc_packed(task->ctrlr->vid, vq->id, task->inflight_idx);