tree 615ec840cef5b8bf209a99304cffe2d6e7e31746
parent 3f5f118bb657f94641ea383c7c1b8c09a5d46ea2
author Pavel Begunkov <asml.silence@gmail.com> 1687523935 +0100
committer Jakub Kicinski <kuba@kernel.org> 1687645441 -0700

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>