If the XSK xmit stops because the TX queue is full, this time is waiting for the TX interrupt to trigger the follow-up work again.
But for Virtio Net, the recycling old buf is not only completed in tx napi, but also is called in start_xmit(), rx poll and other places. So if xsk xmit stop by full tx queue, __free_old_xmit() will try to wakeup tx napi. Signed-off-by: Xuan Zhuo <[email protected]> --- drivers/net/virtio/virtio_net.h | 5 +++-- drivers/net/virtio/xsk.c | 30 ++++++++++++++++++++++++++++++ drivers/net/virtio/xsk.h | 1 + 3 files changed, 34 insertions(+), 2 deletions(-) diff --git a/drivers/net/virtio/virtio_net.h b/drivers/net/virtio/virtio_net.h index fc7c7a0f3c89..100ce48c6d55 100644 --- a/drivers/net/virtio/virtio_net.h +++ b/drivers/net/virtio/virtio_net.h @@ -176,6 +176,8 @@ struct send_queue { dma_addr_t hdr_dma_address; u32 last_cpu; + + bool need_wakeup; } xsk; }; @@ -296,8 +298,7 @@ static void __free_old_xmit(struct send_queue *sq, bool in_napi, stats->packets++; } - if (xsknum) - xsk_tx_completed(sq->xsk.pool, xsknum); + virtnet_xsk_complete(sq, xsknum, in_napi); } int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp, diff --git a/drivers/net/virtio/xsk.c b/drivers/net/virtio/xsk.c index 27b7f0bb2d34..043b0bf2a5d7 100644 --- a/drivers/net/virtio/xsk.c +++ b/drivers/net/virtio/xsk.c @@ -116,6 +116,7 @@ bool virtnet_xsk_xmit(struct send_queue *sq, struct xsk_buff_pool *pool, bool busy; int ret; + sq->xsk.need_wakeup = false; __free_old_xmit(sq, true, &stats); if (xsk_uses_need_wakeup(pool)) @@ -138,6 +139,13 @@ bool virtnet_xsk_xmit(struct send_queue *sq, struct xsk_buff_pool *pool, * triggered by interrupt. */ busy = false; + + /* tx poll may not be triggered by tx interruption because of + * that start_xmit() and rx poll will try free old xmit that + * cause no tx interruption will be generated. So set + * need_wakeup, then tx poll can be triggered by free_old_xmit. + */ + sq->xsk.need_wakeup = true; break; } @@ -206,6 +214,26 @@ int virtnet_xsk_wakeup(struct net_device *dev, u32 qid, u32 flag) return 0; } +void virtnet_xsk_complete(struct send_queue *sq, u32 num, bool in_napi) +{ + struct xsk_buff_pool *pool; + + rcu_read_lock(); + + pool = rcu_dereference(sq->xsk.pool); + if (pool) { + if (num) + xsk_tx_completed(pool, num); + + if (sq->xsk.need_wakeup) { + sq->xsk.need_wakeup = false; + virtnet_xsk_wakeup_sq(sq, in_napi); + } + } + + rcu_read_unlock(); +} + static int virtnet_rq_bind_xsk_pool(struct virtnet_info *vi, struct receive_queue *rq, struct xsk_buff_pool *pool, struct net_device *dev) { @@ -298,6 +326,8 @@ static int virtnet_xsk_pool_enable(struct net_device *dev, if (err) goto err_rxq; + sq->xsk.need_wakeup = false; + /* Here is already protected by rtnl_lock, so rcu_assign_pointer * is safe. */ diff --git a/drivers/net/virtio/xsk.h b/drivers/net/virtio/xsk.h index 5eece0de3310..f90c28972d72 100644 --- a/drivers/net/virtio/xsk.h +++ b/drivers/net/virtio/xsk.h @@ -19,6 +19,7 @@ static inline u32 ptr_to_xsk(void *ptr) return ((unsigned long)ptr) >> VIRTIO_XSK_FLAG_OFFSET; } +void virtnet_xsk_complete(struct send_queue *sq, u32 num, bool in_napi); int virtnet_xsk_pool_setup(struct net_device *dev, struct netdev_bpf *xdp); bool virtnet_xsk_xmit(struct send_queue *sq, struct xsk_buff_pool *pool, int budget); -- 2.32.0.3.g01195cf9f _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
