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author | Soheil Hassas Yeganeh <soheil@google.com> | 2016-04-27 23:39:01 -0400 |
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committer | David S. Miller <davem@davemloft.net> | 2016-04-28 16:06:10 -0400 |
commit | 0a2cf20c3fb62ad4717276b5303bf831f7b29d54 (patch) | |
tree | 8ac718cd55a6ec72241c647e38856d904797a078 /include | |
parent | 863c1fd9814618eefba02218f8fadf8a430c2a17 (diff) | |
download | linux-0a2cf20c3fb62ad4717276b5303bf831f7b29d54.tar.gz linux-0a2cf20c3fb62ad4717276b5303bf831f7b29d54.tar.bz2 linux-0a2cf20c3fb62ad4717276b5303bf831f7b29d54.zip |
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 <soheil@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Suggested-by: Willem de Bruijn <willemb@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/skbuff.h | 6 |
1 files changed, 1 insertions, 5 deletions
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) /* |