On Thu, Aug 26, 2021 at 04:21:35PM +0800, Li RongQing wrote:
> smp_processor_id()/raw* will be called once each when not
> more queues in virtnet_xdp_get_sq() which is called in
> non-preemptible context, so it's safe to call the function
> smp_processor_id() once.
>
> Signed-off-by: Li RongQing <lirongqing@xxxxxxxxx>
commit log should probably explain why it's a good idea
to replace raw_smp_processor_id with smp_processor_id
in the case of curr_queue_pairs <= nr_cpu_ids.
> ---
> drivers/net/virtio_net.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 2e42210a6503..2a7b368c1da2 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -528,19 +528,20 @@ static int __virtnet_xdp_xmit_one(struct virtnet_info *vi,
> * functions to perfectly solve these three problems at the same time.
> */
> #define virtnet_xdp_get_sq(vi) ({ \
> + int cpu = smp_processor_id(); \
> struct netdev_queue *txq; \
> typeof(vi) v = (vi); \
> unsigned int qp; \
> \
> if (v->curr_queue_pairs > nr_cpu_ids) { \
> qp = v->curr_queue_pairs - v->xdp_queue_pairs; \
> - qp += smp_processor_id(); \
> + qp += cpu; \
> txq = netdev_get_tx_queue(v->dev, qp); \
> __netif_tx_acquire(txq); \
> } else { \
> - qp = smp_processor_id() % v->curr_queue_pairs; \
> + qp = cpu % v->curr_queue_pairs; \
> txq = netdev_get_tx_queue(v->dev, qp); \
> - __netif_tx_lock(txq, raw_smp_processor_id()); \
> + __netif_tx_lock(txq, cpu); \
> } \
> v->sq + qp; \
> })
> --
> 2.33.0.69.gc420321.dirty
>
>
