net/tcp: optimise locking for blocking splice
authorPavel Begunkov <asml.silence@gmail.com>
Fri, 23 Jun 2023 12:38:55 +0000 (13:38 +0100)
committerJakub Kicinski <kuba@kernel.org>
Sat, 24 Jun 2023 22:24:01 +0000 (15:24 -0700)
commit2fe11c9d36ee2f3dc3c642588c5d9a22190674c9
tree615ec840cef5b8bf209a99304cffe2d6e7e31746
parent3f5f118bb657f94641ea383c7c1b8c09a5d46ea2
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 <asml.silence@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/80736a2cc6d478c383ea565ba825eaf4d1abd876.1687523671.git.asml.silence@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net/ipv4/tcp.c