From 9bacd256f1354883d3c1402655153367982bba49 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 17 Apr 2020 07:10:23 -0700 Subject: [PATCH] tcp: cache line align MAX_TCP_HEADER TCP stack is dumb in how it cooks its output packets. Depending on MAX_HEADER value, we might chose a bad ending point for the headers. If we align the end of TCP headers to cache line boundary, we make sure to always use the smallest number of cache lines, which always help. Signed-off-by: Eric Dumazet Cc: Soheil Hassas Yeganeh Acked-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller --- include/net/tcp.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index 5fa9eacd965a4a..dcf9a72eeaa691 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -51,7 +51,7 @@ extern struct inet_hashinfo tcp_hashinfo; extern struct percpu_counter tcp_orphan_count; void tcp_time_wait(struct sock *sk, int state, int timeo); -#define MAX_TCP_HEADER (128 + MAX_HEADER) +#define MAX_TCP_HEADER L1_CACHE_ALIGN(128 + MAX_HEADER) #define MAX_TCP_OPTION_SPACE 40 #define TCP_MIN_SND_MSS 48 #define TCP_MIN_GSO_SIZE (TCP_MIN_SND_MSS - MAX_TCP_OPTION_SPACE)