From 4f693b55c3d2d2239b8a0094b518a1e533cf75d5 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 27 Nov 2018 14:42:03 -0800 Subject: tcp: implement coalescing on backlog queue In case GRO is not as efficient as it should be or disabled, we might have a user thread trapped in __release_sock() while softirq handler flood packets up to the point we have to drop. This patch balances work done from user thread and softirq, to give more chances to __release_sock() to complete its work before new packets are added the the backlog. This also helps if we receive many ACK packets, since GRO does not aggregate them. This patch brings ~60% throughput increase on a receiver without GRO, but the spectacular gain is really on 1000x release_sock() latency reduction I have measured. Signed-off-by: Eric Dumazet Cc: Neal Cardwell Cc: Yuchung Cheng Acked-by: Neal Cardwell Signed-off-by: David S. Miller --- include/uapi/linux/snmp.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/uapi/linux/snmp.h') diff --git a/include/uapi/linux/snmp.h b/include/uapi/linux/snmp.h index f80135e5feaa..86dc24a96c90 100644 --- a/include/uapi/linux/snmp.h +++ b/include/uapi/linux/snmp.h @@ -243,6 +243,7 @@ enum LINUX_MIB_TCPREQQFULLDROP, /* TCPReqQFullDrop */ LINUX_MIB_TCPRETRANSFAIL, /* TCPRetransFail */ LINUX_MIB_TCPRCVCOALESCE, /* TCPRcvCoalesce */ + LINUX_MIB_TCPBACKLOGCOALESCE, /* TCPBacklogCoalesce */ LINUX_MIB_TCPOFOQUEUE, /* TCPOFOQueue */ LINUX_MIB_TCPOFODROP, /* TCPOFODrop */ LINUX_MIB_TCPOFOMERGE, /* TCPOFOMerge */ -- cgit v1.2.3