Author: rwatson
Date: Sun Jul 22 17:31:36 2012
New Revision: 238699
URL: http://svn.freebsd.org/changeset/base/238699
Log:
Update some stale comments regarding tcbinfo locking in the TCP input
path: read locks on tcbinfo are no longer used, so won't happen. No
functional change.
MFC after: 3 days
Modified:
head/sys/netinet/tcp_input.c
Modified: head/sys/netinet/tcp_input.c
==============================================================================
--- head/sys/netinet/tcp_input.c Sun Jul 22 16:56:59 2012
(r238698)
+++ head/sys/netinet/tcp_input.c Sun Jul 22 17:31:36 2012
(r238699)
@@ -909,7 +909,7 @@ findpcb:
/*
* A previous connection in TIMEWAIT state is supposed to catch stray
* or duplicate segments arriving late. If this segment was a
- * legitimate new connection attempt the old INPCB gets removed and
+ * legitimate new connection attempt, the old INPCB gets removed and
* we can try again to find a listening socket.
*
* At this point, due to earlier optimism, we may hold only an inpcb
@@ -1438,15 +1438,8 @@ tcp_do_segment(struct mbuf *m, struct tc
/*
* If this is either a state-changing packet or current state isn't
* established, we require a write lock on tcbinfo. Otherwise, we
- * allow either a read lock or a write lock, as we may have acquired
- * a write lock due to a race.
- *
- * Require a global write lock for SYN/FIN/RST segments or
- * non-established connections; otherwise accept either a read or
- * write lock, as we may have conservatively acquired a write lock in
- * certain cases in tcp_input() (is this still true?). Currently we
- * will never enter with no lock, so we try to drop it quickly in the
- * common pure ack/pure data cases.
+ * allow the tcbinfo to be in either alocked or unlocked, as the
+ * caller may have unnecessarily acquired a write lock due to a race.
*/
if ((thflags & (TH_SYN | TH_FIN | TH_RST)) != 0 ||
tp->t_state != TCPS_ESTABLISHED) {
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