From bb4d991a28cc86a2dfbeefeff32911ca9f779c18 Mon Sep 17 00:00:00 2001 From: Yuchung Cheng Date: Wed, 19 Jul 2017 15:41:26 -0700 Subject: tcp: adjust tail loss probe timeout This patch adjusts the timeout formula to schedule the TCP loss probe (TLP). The previous formula uses 2*SRTT or 1.5*RTT + DelayACKMax if only one packet is in flight. It keeps a lower bound of 10 msec which is too large for short RTT connections (e.g. within a data-center). The new formula = 2*RTT + (inflight == 1 ? 200ms : 2ticks) which performs better for short and fast connections. Signed-off-by: Yuchung Cheng Signed-off-by: Neal Cardwell Signed-off-by: David S. Miller --- include/net/tcp.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'include') diff --git a/include/net/tcp.h b/include/net/tcp.h index 70483296157f..4f056ea79df2 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -139,6 +139,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo); #endif #define TCP_RTO_MAX ((unsigned)(120*HZ)) #define TCP_RTO_MIN ((unsigned)(HZ/5)) +#define TCP_TIMEOUT_MIN (2U) /* Min timeout for TCP timers in jiffies */ #define TCP_TIMEOUT_INIT ((unsigned)(1*HZ)) /* RFC6298 2.1 initial RTO value */ #define TCP_TIMEOUT_FALLBACK ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value, now * used as a fallback RTO for the @@ -150,8 +151,6 @@ void tcp_time_wait(struct sock *sk, int state, int timeo); #define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes * for local resources. */ -#define TCP_REO_TIMEOUT_MIN (2000) /* Min RACK reordering timeout in usec */ - #define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */ #define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */ #define TCP_KEEPALIVE_INTVL (75*HZ) -- cgit v1.2.3