svn commit: r196294 - in stable/8/sys: . amd64/include/xen cddl/contrib/opensolaris contrib/dev/acpica contrib/pf dev/ata dev/cxgb dev/mfi dev/xen/netfront dev/xen/xenpci kern modules/dtrace/dtnfsc...

[Pawel Jakub Dawidek]

Author: pjd
Date: Mon Aug 17 08:46:47 2009
New Revision: 196294
URL: http://svn.freebsd.org/changeset/base/196294

Log:
  MFC r196293:
  
  Because taskqueue_run() can drop tq_mutex, we need to check if the
  TQ_FLAGS_ACTIVE flag wasn't removed in the meantime, which means we missed a
  wakeup.
  
  Approved by:	re (kib)

Modified:
  stable/8/sys/   (props changed)
  stable/8/sys/amd64/include/xen/   (props changed)
  stable/8/sys/cddl/contrib/opensolaris/   (props changed)
  stable/8/sys/contrib/dev/acpica/   (props changed)
  stable/8/sys/contrib/pf/   (props changed)
  stable/8/sys/dev/ata/   (props changed)
  stable/8/sys/dev/cxgb/   (props changed)
  stable/8/sys/dev/mfi/   (props changed)
  stable/8/sys/dev/xen/netfront/   (props changed)
  stable/8/sys/dev/xen/xenpci/   (props changed)
  stable/8/sys/kern/subr_taskqueue.c
  stable/8/sys/modules/dtrace/dtnfsclient/   (props changed)
  stable/8/sys/modules/ip6_mroute_mod/   (props changed)
  stable/8/sys/modules/ipmi/ipmi_linux/   (props changed)
  stable/8/sys/netinet/ipfw/ip_dummynet.c   (props changed)
  stable/8/sys/netinet/ipfw/ip_fw2.c   (props changed)
  stable/8/sys/netinet/ipfw/ip_fw_nat.c   (props changed)
  stable/8/sys/netinet/ipfw/ip_fw_pfil.c   (props changed)
  stable/8/sys/netipx/spx_reass.c   (props changed)
  stable/8/sys/xen/evtchn.h   (props changed)
  stable/8/sys/xen/hypervisor.h   (props changed)
  stable/8/sys/xen/xen_intr.h   (props changed)

Modified: stable/8/sys/kern/subr_taskqueue.c
==============================================================================
--- stable/8/sys/kern/subr_taskqueue.c	Mon Aug 17 08:42:34 2009	(r196293)
+++ stable/8/sys/kern/subr_taskqueue.c	Mon Aug 17 08:46:47 2009	(r196294)
@@ -401,6 +401,13 @@ taskqueue_thread_loop(void *arg)
 	TQ_LOCK(tq);
 	while ((tq->tq_flags & TQ_FLAGS_ACTIVE) != 0) {
 		taskqueue_run(tq);
+		/*
+		 * Because taskqueue_run() can drop tq_mutex, we need to
+		 * check if the TQ_FLAGS_ACTIVE flag wasn't removed in the
+		 * meantime, which means we missed a wakeup.
+		 */
+		if ((tq->tq_flags & TQ_FLAGS_ACTIVE) == 0)
+			break;
 		TQ_SLEEP(tq, tq, &tq->tq_mutex, 0, "-", 0);
 	}