Author: lstewart
Date: Sat Nov 27 03:12:39 2010
New Revision: 215926
URL: http://svn.freebsd.org/changeset/base/215926
Log:
Partially MFC r215166:
Disable priming the congestion window from the host cache. The current method
interacts poorly with delayed ack amongst other things, resulting in undesired
delay during a connection's opening slow start. Even if we did fix the
issues,
the current method is still dubious at best and needs to be thought through
thoroughly.
Due to a mistake on my behalf, the change described above was committed to
head
as part of a larger patch in revision 215166. Instead of waiting for the MFC
of
215166, I'm merging just this small portion for the upcoming release without
bringing the mergeinfo for r215166 along. The mergeinfo will sort itself out
when r215166 is eventually merged.
This is an intentional direct commit to the 7-STABLE branch.
Reported by: Maxim Dounin <mdounin at mdounin ru> and others
Submitted by: andre
Modified:
stable/7/sys/netinet/tcp_input.c
Modified: stable/7/sys/netinet/tcp_input.c
==============================================================================
--- stable/7/sys/netinet/tcp_input.c Sat Nov 27 02:18:55 2010
(r215925)
+++ stable/7/sys/netinet/tcp_input.c Sat Nov 27 03:12:39 2010
(r215926)
@@ -2987,10 +2987,14 @@ tcp_mss(struct tcpcb *tp, int offer)
* hostcache when cwnd collapses so next connection doesn't
* overloads the path again.
*
+ * XXXAO: Initializing the CWND from the hostcache is broken
+ * and in its current form not RFC conformant. It is disabled
+ * until fixed or removed entirely.
+ *
* RFC3390 says only do this if SYN or SYN/ACK didn't got lost.
* We currently check only in syncache_socket for that.
*/
-#define TCP_METRICS_CWND
+/* #define TCP_METRICS_CWND */
#ifdef TCP_METRICS_CWND
if (metrics.rmx_cwnd)
tp->snd_cwnd = max(mss,
_______________________________________________
[email protected] mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "[email protected]"
