From 5f23b734963ec7eaa3ebcd9050da0c9b7d143dd3 Mon Sep 17 00:00:00 2001 From: dann frazier Date: Wed, 26 Nov 2008 15:32:27 -0800 Subject: net: Fix soft lockups/OOM issues w/ unix garbage collector This is an implementation of David Miller's suggested fix in: https://bugzilla.redhat.com/show_bug.cgi?id=470201 It has been updated to use wait_event() instead of wait_event_interruptible(). Paraphrasing the description from the above report, it makes sendmsg() block while UNIX garbage collection is in progress. This avoids a situation where child processes continue to queue new FDs over a AF_UNIX socket to a parent which is in the exit path and running garbage collection on these FDs. This contention can result in soft lockups and oom-killing of unrelated processes. Signed-off-by: dann frazier Signed-off-by: David S. Miller --- net/unix/af_unix.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net/unix/af_unix.c') diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index eb90f77bb0e2..66d5ac4773ab 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -1343,6 +1343,7 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, if (NULL == siocb->scm) siocb->scm = &tmp_scm; + wait_for_unix_gc(); err = scm_send(sock, msg, siocb->scm); if (err < 0) return err; @@ -1493,6 +1494,7 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, if (NULL == siocb->scm) siocb->scm = &tmp_scm; + wait_for_unix_gc(); err = scm_send(sock, msg, siocb->scm); if (err < 0) return err; -- cgit v1.2.2