diff mbox series

[net-next,19/20] tcp: do not call tcp_cleanup_rbuf() if we have a backlog

Message ID 20211115190249.3936899-20-eric.dumazet@gmail.com (mailing list archive)
State Accepted
Delegated to: Netdev Maintainers
Headers show
Series tcp: optimizations for linux-5.17 | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count fail Series longer than 15 patches (and no cover letter)
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 2 this patch: 2
netdev/cc_maintainers warning 2 maintainers not CCed: yoshfuji@linux-ipv6.org dsahern@kernel.org
netdev/build_clang success Errors and warnings before: 22 this patch: 22
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 6 this patch: 6
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 13 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Eric Dumazet Nov. 15, 2021, 7:02 p.m. UTC 
From: Eric Dumazet <edumazet@google.com>

Under pressure, tcp recvmsg() has logic to process the socket backlog,
but calls tcp_cleanup_rbuf() right before.

Avoiding sending ACK right before processing new segments makes
a lot of sense, as this decrease the number of ACK packets,
with no impact on effective ACK clocking.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/ipv4/tcp.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 7b1886103556e1295d84378d5bcb0f0346651de0..d1949fdb1462b97b87b99bc32ea132c574e9b647 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2436,12 +2436,11 @@  static int tcp_recvmsg_locked(struct sock *sk, struct msghdr *msg, size_t len,
 			}
 		}
 
-		tcp_cleanup_rbuf(sk, copied);
-
 		if (copied >= target) {
 			/* Do not sleep, just process backlog. */
 			__sk_flush_backlog(sk);
 		} else {
+			tcp_cleanup_rbuf(sk, copied);
 			sk_defer_free_flush(sk);
 			sk_wait_data(sk, &timeo, last);
 		}