> -----Original Message-----
> From: Tyler Retzlaff <roret...@linux.microsoft.com>
> Sent: Thursday, March 2, 2023 8:48 AM
> To: dev@dpdk.org
> Cc: Honnappa Nagarahalli <honnappa.nagaraha...@arm.com>; tho...@monjalon.net;
> Tyler
> Retzlaff <roret...@linux.microsoft.com>
> Subject: [PATCH 11/17] net/iavf: use previous value atomic fetch operations
>
> 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 <roret...@linux.microsoft.com>
> ---
> drivers/net/iavf/iavf_vchnl.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/iavf/iavf_vchnl.c b/drivers/net/iavf/iavf_vchnl.c
> index
> 9adaadb..73875d7 100644
> --- a/drivers/net/iavf/iavf_vchnl.c
> +++ b/drivers/net/iavf/iavf_vchnl.c
> @@ -128,7 +128,7 @@ struct iavf_event_handler {
> int err = pipe(handler->fd);
> #endif
> if (err != 0) {
> - __atomic_sub_fetch(&handler->ndev, 1, __ATOMIC_RELAXED);
> + __atomic_fetch_sub(&handler->ndev, 1, __ATOMIC_RELAXED);
> return -1;
> }
>
> @@ -137,7 +137,7 @@ struct iavf_event_handler {
>
> if (rte_ctrl_thread_create(&handler->tid, "iavf-event-thread",
> NULL, iavf_dev_event_handle, NULL)) {
> - __atomic_sub_fetch(&handler->ndev, 1, __ATOMIC_RELAXED);
> + __atomic_fetch_sub(&handler->ndev, 1, __ATOMIC_RELAXED);
> return -1;
> }
>
> @@ -533,7 +533,7 @@ struct iavf_event_handler {
> /* read message and it's expected one */
> if (msg_opc == vf->pend_cmd) {
> uint32_t cmd_count =
> - __atomic_sub_fetch(&vf->pend_cmd_count,
> + __atomic_fetch_sub(&vf->pend_cmd_count,
It doesn't apply here. The return value is used.
The rest of the series looks good to me.
> 1, __ATOMIC_RELAXED);
> if (cmd_count == 0)
> _notify_cmd(vf, msg_ret);
> --
> 1.8.3.1
