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From: Hiren Panchasara <hiren@FreeBSD.org>
Date: Sat, 9 Aug 2014 21:01:24 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
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Subject: svn commit: r269766 - head/sys/netinet
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Author: hiren
Date: Sat Aug  9 21:01:24 2014
New Revision: 269766
URL: http://svnweb.freebsd.org/changeset/base/269766

Log:
  Improve comments by listing a criteria for automatic increment of receive socket
  buffer.
  
  Reviewed by:	jmg

Modified:
  head/sys/netinet/tcp_input.c

Modified: head/sys/netinet/tcp_input.c
==============================================================================
--- head/sys/netinet/tcp_input.c	Sat Aug  9 20:40:03 2014	(r269765)
+++ head/sys/netinet/tcp_input.c	Sat Aug  9 21:01:24 2014	(r269766)
@@ -1793,11 +1793,13 @@ tcp_do_segment(struct mbuf *m, struct tc
 		 * reassembly queue.
 		 *
 		 * The criteria to step up the receive buffer one notch are:
-		 *  1. the number of bytes received during the time it takes
+		 *  1. Application has not set receive buffer size with
+		 *     SO_RCVBUF. Setting SO_RCVBUF clears SB_AUTOSIZE.
+		 *  2. the number of bytes received during the time it takes
 		 *     one timestamp to be reflected back to us (the RTT);
-		 *  2. received bytes per RTT is within seven eighth of the
+		 *  3. received bytes per RTT is within seven eighth of the
 		 *     current socket buffer size;
-		 *  3. receive buffer size has not hit maximal automatic size;
+		 *  4. receive buffer size has not hit maximal automatic size;
 		 *
 		 * This algorithm does one step per RTT at most and only if
 		 * we receive a bulk stream w/o packet losses or reorderings.