svn commit: r360020 - in head/sys: netinet netinet6

[Jonathan T. Looney]

Author: jtl
Date: Thu Apr 16 20:17:24 2020
New Revision: 360020
URL: https://svnweb.freebsd.org/changeset/base/360020

Log:
  Avoid calling protocol drain routines more than once per reclamation event.
  
  mb_reclaim() calls the protocol drain routines for each protocol in each
  domain. Some protocols exist in more than one domain and share drain
  routines. In the case of SCTP, it also uses the same drain routine for
  its SOCK_SEQPACKET and SOCK_STREAM entries in the same domain.
  
  On systems with INET, INET6, and SCTP all defined, mb_reclaim() calls
  sctp_drain() four times. On systems with INET and INET6 defined,
  mb_reclaim() calls tcp_drain() twice. mb_reclaim() is the only in-tree
  caller of the pr_drain protocol entry.
  
  Eliminate this duplication by ensuring that each pr_drain routine is only
  specified for one protocol entry in one domain.
  
  Reviewed by:	tuexen
  MFC after:	2 weeks
  Sponsored by:	Netflix, Inc.
  Differential Revision:	https://reviews.freebsd.org/D24418

Modified:
  head/sys/netinet/in_proto.c
  head/sys/netinet6/in6_proto.c

Modified: head/sys/netinet/in_proto.c
==============================================================================
--- head/sys/netinet/in_proto.c	Thu Apr 16 20:07:34 2020	(r360019)
+++ head/sys/netinet/in_proto.c	Thu Apr 16 20:17:24 2020	(r360020)
@@ -163,7 +163,7 @@ struct protosw inetsw[] = {
 	.pr_input =		sctp_input,
 	.pr_ctlinput =		sctp_ctlinput,
 	.pr_ctloutput =		sctp_ctloutput,
-	.pr_drain =		sctp_drain,
+	.pr_drain =		NULL, /* Covered by the SOCK_SEQPACKET entry. */
 	.pr_usrreqs =		&sctp_usrreqs
 },
 #endif /* SCTP */

Modified: head/sys/netinet6/in6_proto.c
==============================================================================
--- head/sys/netinet6/in6_proto.c	Thu Apr 16 20:07:34 2020	(r360019)
+++ head/sys/netinet6/in6_proto.c	Thu Apr 16 20:17:24 2020	(r360020)
@@ -172,11 +172,11 @@ struct protosw inet6sw[] = {
 	.pr_input =		tcp6_input,
 	.pr_ctlinput =		tcp6_ctlinput,
 	.pr_ctloutput =		tcp_ctloutput,
-#ifndef INET	/* don't call initialization and timeout routines twice */
+#ifndef INET	/* don't call initialization, timeout, and drain routines twice */
 	.pr_init =		tcp_init,
 	.pr_slowtimo =		tcp_slowtimo,
-#endif
 	.pr_drain =		tcp_drain,
+#endif
 	.pr_usrreqs =		&tcp6_usrreqs,
 },
 #ifdef SCTP
@@ -188,8 +188,8 @@ struct protosw inet6sw[] = {
 	.pr_input =		sctp6_input,
 	.pr_ctlinput =		sctp6_ctlinput,
 	.pr_ctloutput =	sctp_ctloutput,
+#ifndef INET	/* Do not call initialization and drain routines twice. */
 	.pr_drain =		sctp_drain,
-#ifndef INET	/* Do not call initialization twice. */
 	.pr_init =		sctp_init,
 #endif
 	.pr_usrreqs =		&sctp6_usrreqs
@@ -202,7 +202,7 @@ struct protosw inet6sw[] = {
 	.pr_input =		sctp6_input,
 	.pr_ctlinput =		sctp6_ctlinput,
 	.pr_ctloutput =		sctp_ctloutput,
-	.pr_drain =		sctp_drain,
+	.pr_drain =		NULL, /* Covered by the SOCK_SEQPACKET entry. */
 	.pr_usrreqs =		&sctp6_usrreqs
 },
 #endif /* SCTP */