From 0a2cf20c3fb62ad4717276b5303bf831f7b29d54 Mon Sep 17 00:00:00 2001 From: Soheil Hassas Yeganeh Date: Wed, 27 Apr 2016 23:39:01 -0400 Subject: tcp: remove SKBTX_ACK_TSTAMP since it is redundant The SKBTX_ACK_TSTAMP flag is set in skb_shinfo->tx_flags when the timestamp of the TCP acknowledgement should be reported on error queue. Since accessing skb_shinfo is likely to incur a cache-line miss at the time of receiving the ack, the txstamp_ack bit was added in tcp_skb_cb, which is set iff the SKBTX_ACK_TSTAMP flag is set for an skb. This makes SKBTX_ACK_TSTAMP flag redundant. Remove the SKBTX_ACK_TSTAMP and instead use the txstamp_ack bit everywhere. Note that this frees one bit in shinfo->tx_flags. Signed-off-by: Soheil Hassas Yeganeh Acked-by: Martin KaFai Lau Suggested-by: Willem de Bruijn Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- include/linux/skbuff.h | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'include/linux/skbuff.h') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index a1ce63979ad8..c84a5a1078c5 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -382,14 +382,10 @@ enum { /* generate software time stamp when entering packet scheduling */ SKBTX_SCHED_TSTAMP = 1 << 6, - - /* generate software timestamp on peer data acknowledgment */ - SKBTX_ACK_TSTAMP = 1 << 7, }; #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \ - SKBTX_SCHED_TSTAMP | \ - SKBTX_ACK_TSTAMP) + SKBTX_SCHED_TSTAMP) #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP) /* -- cgit v1.2.1