From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: [PATCH] tcp: do not expire TCP fastopen cookies Date: Fri, 03 May 2013 22:12:45 -0700 Message-ID: <1367644365.22983.12.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev , Yuchung Cheng , Neal Cardwell To: David Miller Return-path: Received: from mail-pd0-f174.google.com ([209.85.192.174]:32926 "EHLO mail-pd0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751542Ab3EDFMs (ORCPT ); Sat, 4 May 2013 01:12:48 -0400 Received: by mail-pd0-f174.google.com with SMTP id u10so1221164pdi.33 for ; Fri, 03 May 2013 22:12:47 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet TCP metric cache expires entries after one hour. This probably make sense for TCP RTT/RTTVAR/CWND, but not for TCP fastopen cookies. Its better to try previous cookie. If it appears to be obsolete, server will send us new cookie anyway. Signed-off-by: Eric Dumazet Cc: Yuchung Cheng Cc: Neal Cardwell --- net/ipv4/tcp_metrics.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c index f696d7c..f6a005c 100644 --- a/net/ipv4/tcp_metrics.c +++ b/net/ipv4/tcp_metrics.c @@ -96,7 +96,8 @@ struct tcpm_hash_bucket { static DEFINE_SPINLOCK(tcp_metrics_lock); -static void tcpm_suck_dst(struct tcp_metrics_block *tm, struct dst_entry *dst) +static void tcpm_suck_dst(struct tcp_metrics_block *tm, struct dst_entry *dst, + bool fastopen_clear) { u32 val; @@ -122,9 +123,11 @@ static void tcpm_suck_dst(struct tcp_metrics_block *tm, struct dst_entry *dst) tm->tcpm_vals[TCP_METRIC_REORDERING] = dst_metric_raw(dst, RTAX_REORDERING); tm->tcpm_ts = 0; tm->tcpm_ts_stamp = 0; - tm->tcpm_fastopen.mss = 0; - tm->tcpm_fastopen.syn_loss = 0; - tm->tcpm_fastopen.cookie.len = 0; + if (fastopen_clear) { + tm->tcpm_fastopen.mss = 0; + tm->tcpm_fastopen.syn_loss = 0; + tm->tcpm_fastopen.cookie.len = 0; + } } static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst, @@ -154,7 +157,7 @@ static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst, } tm->tcpm_addr = *addr; - tcpm_suck_dst(tm, dst); + tcpm_suck_dst(tm, dst, true); if (likely(!reclaim)) { tm->tcpm_next = net->ipv4.tcp_metrics_hash[hash].chain; @@ -171,7 +174,7 @@ out_unlock: static void tcpm_check_stamp(struct tcp_metrics_block *tm, struct dst_entry *dst) { if (tm && unlikely(time_after(jiffies, tm->tcpm_stamp + TCP_METRICS_TIMEOUT))) - tcpm_suck_dst(tm, dst); + tcpm_suck_dst(tm, dst, false); } #define TCP_METRICS_RECLAIM_DEPTH 5