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| author | Soheil Hassas Yeganeh <soheil@google.com> | 2016-04-27 23:39:01 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-04-28 16:06:10 -0400 |
| commit | 0a2cf20c3fb62ad4717276b5303bf831f7b29d54 (patch) | |
| tree | 8ac718cd55a6ec72241c647e38856d904797a078 /net/ipv4/tcp_input.c | |
| 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 'net/ipv4/tcp_input.c')
| -rw-r--r-- | net/ipv4/tcp_input.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 0d5239c283cb..70c370b93762 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3087,8 +3087,7 @@ static void tcp_ack_tstamp(struct sock *sk, struct sk_buff *skb, return; shinfo = skb_shinfo(skb); - if ((shinfo->tx_flags & SKBTX_ACK_TSTAMP) && - !before(shinfo->tskey, prior_snd_una) && + if (!before(shinfo->tskey, prior_snd_una) && before(shinfo->tskey, tcp_sk(sk)->snd_una)) __skb_tstamp_tx(skb, NULL, sk, SCM_TSTAMP_ACK); } |