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From: Joyce Kong <joyce.kong@arm.com>
To: maxime.coquelin@redhat.com, chenbo.xia@intel.com,
honnappa.nagarahalli@arm.com, ruifeng.wang@arm.com
Cc: dev@dpdk.org,
nd@arm.com
Date: Mon, 21 Dec 2020 23:50:32 +0800
Message-Id: <20201221155033.6771-8-joyce.kong@arm.com>
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Subject: [dpdk-dev] [PATCH v1 7/8] vhost: replace smp with thread fence for
packed vring
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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(-)
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;
--
2.29.2