diff mbox series

[v1,7/8] vhost: replace smp with thread fence for packed vring

Message ID 20201221155033.6771-8-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

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Joyce Kong Dec. 21, 2020, 3:50 p.m. UTC 
Simply relace smp barriers with atomic thread fence for
virtio packed vring.

Signed-off-by: Joyce Kong <joyce.kong@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
---
 lib/librte_vhost/virtio_net.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

Comments

Maxime Coquelin Jan. 7, 2021, 5:06 p.m. UTC | #1 
On 12/21/20 4:50 PM, Joyce Kong wrote:
> Simply relace smp barriers with atomic thread fence for
> virtio packed vring.
> 
> Signed-off-by: Joyce Kong <joyce.kong@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> ---
>  lib/librte_vhost/virtio_net.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 

Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Thanks,
Maxime
diff mbox series

Patch

diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index b779034dc..e145fcbc2 100644
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -171,7 +171,8 @@  vhost_flush_enqueue_shadow_packed(struct virtio_net *dev,
 			used_idx -= vq->size;
 	}
 
-	rte_smp_wmb();
+	/* The ordering for storing desc flags needs to be enforced. */
+	rte_atomic_thread_fence(__ATOMIC_RELEASE);
 
 	for (i = 0; i < vq->shadow_used_idx; i++) {
 		uint16_t flags;
@@ -254,7 +255,7 @@  vhost_flush_enqueue_batch_packed(struct virtio_net *dev,
 		vq->desc_packed[vq->last_used_idx + i].len = lens[i];
 	}
 
-	rte_smp_wmb();
+	rte_atomic_thread_fence(__ATOMIC_RELEASE);
 
 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
 		vq->desc_packed[vq->last_used_idx + i].flags = flags;
@@ -313,7 +314,7 @@  vhost_shadow_dequeue_batch_packed(struct virtio_net *dev,
 		vq->desc_packed[vq->last_used_idx + i].len = 0;
 	}
 
-	rte_smp_wmb();
+	rte_atomic_thread_fence(__ATOMIC_RELEASE);
 	vhost_for_each_try_unroll(i, begin, PACKED_BATCH_SIZE)
 		vq->desc_packed[vq->last_used_idx + i].flags = flags;
 
@@ -2246,7 +2247,7 @@  vhost_reserve_avail_batch_packed(struct virtio_net *dev,
 			return -1;
 	}
 
-	rte_smp_rmb();
+	rte_atomic_thread_fence(__ATOMIC_ACQUIRE);
 
 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
 		lens[i] = descs[avail_idx + i].len;