From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: Tyler Retzlaff <roretzla@linux.microsoft.com>, dev@dpdk.org
Cc: Honnappa.Nagarahalli@arm.com, thomas@monjalon.net
Subject: Re: [PATCH 01/17] vhost: use previous value atomic fetch operations
Date: Thu, 2 Mar 2023 15:47:18 +0100 [thread overview]
Message-ID: <adad6ff8-a056-b4a6-1083-a572aa35049c@redhat.com> (raw)
In-Reply-To: <1677718068-2412-2-git-send-email-roretzla@linux.microsoft.com>
On 3/2/23 01:47, Tyler Retzlaff wrote:
> Use __atomic_fetch_{add,and,or,sub,xor} instead of
> __atomic_{add,and,or,sub,xor}_fetch when we have no interest in the
> result of the operation.
>
> Reduces unnecessary codegen that provided the result of the atomic
> operation that was not used.
>
> Change brings closer alignment with atomics available in C11 standard
> and will reduce review effort when they are integrated.
>
> Signed-off-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
> ---
> lib/vhost/virtio_net.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c
> index 51dc3c9..dc49a54 100644
> --- a/lib/vhost/virtio_net.c
> +++ b/lib/vhost/virtio_net.c
> @@ -298,7 +298,7 @@
>
> vhost_log_cache_sync(dev, vq);
>
> - __atomic_add_fetch(&vq->used->idx, vq->shadow_used_idx,
> + __atomic_fetch_add(&vq->used->idx, vq->shadow_used_idx,
> __ATOMIC_RELEASE);
> vq->shadow_used_idx = 0;
> vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
> @@ -2311,7 +2311,7 @@
> vhost_vring_call_packed(dev, vq);
> } else {
> write_back_completed_descs_split(vq, n_descs);
> - __atomic_add_fetch(&vq->used->idx, n_descs, __ATOMIC_RELEASE);
> + __atomic_fetch_add(&vq->used->idx, n_descs, __ATOMIC_RELEASE);
> vhost_vring_call_split(dev, vq);
> }
> } else {
> @@ -3683,7 +3683,7 @@
> vhost_vring_call_packed(dev, vq);
> } else {
> write_back_completed_descs_split(vq, nr_cpl_pkts);
> - __atomic_add_fetch(&vq->used->idx, nr_cpl_pkts, __ATOMIC_RELEASE);
> + __atomic_fetch_add(&vq->used->idx, nr_cpl_pkts, __ATOMIC_RELEASE);
> vhost_vring_call_split(dev, vq);
> }
> vq->async->pkts_inflight_n -= nr_cpl_pkts;
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Thanks,
Maxime
next prev parent reply other threads:[~2023-03-02 14:47 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-02 0:47 [PATCH 00/17] use __atomic operations returning previous value Tyler Retzlaff
2023-03-02 0:47 ` [PATCH 01/17] vhost: use previous value atomic fetch operations Tyler Retzlaff
2023-03-02 14:47 ` Maxime Coquelin [this message]
2023-03-02 0:47 ` [PATCH 02/17] telemetry: " Tyler Retzlaff
2023-03-02 9:34 ` Bruce Richardson
2023-03-02 0:47 ` [PATCH 03/17] stack: " Tyler Retzlaff
2023-03-02 0:47 ` [PATCH 04/17] eal: " Tyler Retzlaff
2023-03-02 0:47 ` [PATCH 05/17] distributor: " Tyler Retzlaff
2023-03-02 0:47 ` [PATCH 06/17] bbdev: " Tyler Retzlaff
2023-03-02 0:47 ` [PATCH 07/17] examples/vhost: " Tyler Retzlaff
2023-03-02 14:47 ` Maxime Coquelin
2023-03-02 0:47 ` [PATCH 08/17] net/virtio: " Tyler Retzlaff
2023-03-02 14:48 ` Maxime Coquelin
2023-03-02 0:47 ` [PATCH 09/17] net/octeontx: " Tyler Retzlaff
2023-03-02 0:47 ` [PATCH 10/17] net/mlx5: " Tyler Retzlaff
2023-03-02 0:47 ` [PATCH 11/17] net/iavf: " Tyler Retzlaff
2023-03-02 9:28 ` Ruifeng Wang
2023-03-02 15:50 ` Tyler Retzlaff
2023-03-02 0:47 ` [PATCH 12/17] net/cxgbe: " Tyler Retzlaff
2023-03-02 0:47 ` [PATCH 13/17] drivers/event: " Tyler Retzlaff
2023-03-02 0:47 ` [PATCH 14/17] dma/skeleton: " Tyler Retzlaff
2023-03-02 0:47 ` [PATCH 15/17] drivers/common: " Tyler Retzlaff
2023-03-02 0:47 ` [PATCH 16/17] app/test: " Tyler Retzlaff
2023-03-02 0:47 ` [PATCH 17/17] test-eventdev: " Tyler Retzlaff
2023-03-02 14:40 ` [PATCH 00/17] use __atomic operations returning previous value Morten Brørup
2023-03-02 16:18 ` [PATCH v2 " Tyler Retzlaff
2023-03-02 16:18 ` [PATCH v2 01/17] vhost: use previous value atomic fetch operations Tyler Retzlaff
2023-03-02 16:18 ` [PATCH v2 02/17] telemetry: " Tyler Retzlaff
2023-03-02 16:18 ` [PATCH v2 03/17] stack: " Tyler Retzlaff
2023-03-02 16:18 ` [PATCH v2 04/17] eal: " Tyler Retzlaff
2023-03-02 16:18 ` [PATCH v2 05/17] distributor: " Tyler Retzlaff
2023-03-02 16:18 ` [PATCH v2 06/17] bbdev: " Tyler Retzlaff
2023-03-02 16:18 ` [PATCH v2 07/17] examples/vhost: " Tyler Retzlaff
2023-03-02 16:18 ` [PATCH v2 08/17] net/virtio: " Tyler Retzlaff
2023-03-02 16:18 ` [PATCH v2 09/17] net/octeontx: " Tyler Retzlaff
2023-03-02 16:18 ` [PATCH v2 10/17] net/mlx5: " Tyler Retzlaff
2023-03-02 16:18 ` [PATCH v2 11/17] net/iavf: " Tyler Retzlaff
2023-03-02 16:18 ` [PATCH v2 12/17] net/cxgbe: " Tyler Retzlaff
2023-03-02 16:18 ` [PATCH v2 13/17] drivers/event: " Tyler Retzlaff
2023-03-13 7:02 ` [EXT] " Pavan Nikhilesh Bhagavatula
2023-03-02 16:18 ` [PATCH v2 14/17] dma/skeleton: " Tyler Retzlaff
2023-03-02 16:18 ` [PATCH v2 15/17] drivers/common: " Tyler Retzlaff
2023-03-02 16:18 ` [PATCH v2 16/17] app/test: " Tyler Retzlaff
2023-03-02 16:18 ` [PATCH v2 17/17] test-eventdev: " Tyler Retzlaff
2023-03-03 1:54 ` [PATCH v2 00/17] use __atomic operations returning previous value Ruifeng Wang
2023-03-03 2:33 ` fengchengwen
2023-04-25 9:10 ` David Marchand
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