| Message ID | 1633771963-6746-1-git-send-email-lirongqing@baidu.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 6213f07cb542c9651ba614e784bf58ed41354936 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next] virtio_net: skip RCU read lock by checking xdp_enabled of vi | expand |
Hello: This patch was applied to netdev/net-next.git (master) by David S. Miller <davem@davemloft.net>: On Sat, 9 Oct 2021 17:32:43 +0800 you wrote: > networking benchmark shows that __rcu_read_lock and > __rcu_read_unlock takes some cpu cycles, and we can avoid > calling them partially in virtio rx path by check xdp_enabled > of vi, and xdp is disabled most of time > > Signed-off-by: Li RongQing <lirongqing@baidu.com> > > [...] Here is the summary with links: - [net-next] virtio_net: skip RCU read lock by checking xdp_enabled of vi https://git.kernel.org/netdev/net-next/c/6213f07cb542 You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 2ed49884565f..74d2be438180 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -734,6 +734,12 @@ static struct sk_buff *receive_small(struct net_device *dev, dev->stats.rx_length_errors++; goto err_len; } + + if (likely(!vi->xdp_enabled)) { + xdp_prog = NULL; + goto skip_xdp; + } + rcu_read_lock(); xdp_prog = rcu_dereference(rq->xdp_prog); if (xdp_prog) { @@ -816,6 +822,7 @@ static struct sk_buff *receive_small(struct net_device *dev, } rcu_read_unlock(); +skip_xdp: skb = build_skb(buf, buflen); if (!skb) { put_page(page); @@ -897,6 +904,12 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, dev->stats.rx_length_errors++; goto err_skb; } + + if (likely(!vi->xdp_enabled)) { + xdp_prog = NULL; + goto skip_xdp; + } + rcu_read_lock(); xdp_prog = rcu_dereference(rq->xdp_prog); if (xdp_prog) { @@ -1024,6 +1037,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, } rcu_read_unlock(); +skip_xdp: head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog, metasize, headroom); curr_skb = head_skb;
networking benchmark shows that __rcu_read_lock and __rcu_read_unlock takes some cpu cycles, and we can avoid calling them partially in virtio rx path by check xdp_enabled of vi, and xdp is disabled most of time Signed-off-by: Li RongQing <lirongqing@baidu.com> --- drivers/net/virtio_net.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)