From 2fe11c9d36ee2f3dc3c642588c5d9a22190674c9 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Fri, 23 Jun 2023 13:38:55 +0100 Subject: [PATCH] net/tcp: optimise locking for blocking splice Even when tcp_splice_read() reads all it was asked for, for blocking sockets it'll release and immediately regrab the socket lock, loop around and break on the while check. Check tss.len right after we adjust it, and return if we're done. That saves us one release_sock(); lock_sock(); pair per successful blocking splice read. Signed-off-by: Pavel Begunkov Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/80736a2cc6d478c383ea565ba825eaf4d1abd876.1687523671.git.asml.silence@gmail.com Signed-off-by: Jakub Kicinski --- net/ipv4/tcp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 71b42ee..d56edc2 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -839,7 +839,7 @@ ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos, tss.len -= ret; spliced += ret; - if (!timeo) + if (!tss.len || !timeo) break; release_sock(sk); lock_sock(sk); -- 2.7.4