Module Name: src
Committed By: ozaki-r
Date: Thu Dec 22 12:55:28 UTC 2016
Modified Files:
src/sys/rump/net/lib/libshmif: if_shmem.c
Log Message:
Fix that rump.ifconfig shmifN destroy hangs up
rump.ifconfig shmifN destroy sometimes hangs up on closing a file
descriptor of kqueue under heavy load. It seems it happens because of
a race condition between closing a fd and kevent to the same fd on
another kthread for packet Rx. Fix it by executing the close operation
after the kthread left.
To generate a diff of this commit:
cvs rdiff -u -r1.71 -r1.72 src/sys/rump/net/lib/libshmif/if_shmem.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/rump/net/lib/libshmif/if_shmem.c
diff -u src/sys/rump/net/lib/libshmif/if_shmem.c:1.71 src/sys/rump/net/lib/libshmif/if_shmem.c:1.72
--- src/sys/rump/net/lib/libshmif/if_shmem.c:1.71 Thu Dec 22 10:13:09 2016
+++ src/sys/rump/net/lib/libshmif/if_shmem.c Thu Dec 22 12:55:28 2016
@@ -1,4 +1,4 @@
-/* $NetBSD: if_shmem.c,v 1.71 2016/12/22 10:13:09 ozaki-r Exp $ */
+/* $NetBSD: if_shmem.c,v 1.72 2016/12/22 12:55:28 ozaki-r Exp $ */
/*
* Copyright (c) 2009, 2010 Antti Kantee. All Rights Reserved.
@@ -28,7 +28,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_shmem.c,v 1.71 2016/12/22 10:13:09 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_shmem.c,v 1.72 2016/12/22 12:55:28 ozaki-r Exp $");
#include <sys/param.h>
#include <sys/atomic.h>
@@ -374,7 +374,6 @@ shmif_unclone(struct ifnet *ifp)
shmif_stop(ifp, 1);
if_down(ifp);
- finibackend(sc);
mutex_enter(&sc->sc_mtx);
sc->sc_dying = true;
@@ -385,6 +384,13 @@ shmif_unclone(struct ifnet *ifp)
kthread_join(sc->sc_rcvl);
sc->sc_rcvl = NULL;
+ /*
+ * Need to be called after the kthread left, otherwise closing kqueue
+ * (sc_kq) hangs sometimes perhaps because of a race condition between
+ * close and kevent in the kthread on the kqueue.
+ */
+ finibackend(sc);
+
vmem_xfree(shmif_units, sc->sc_unit+1, 1);
ether_ifdetach(ifp);
