On Sat, Jan 05, 2013 at 06:21:01PM +0100, Frederic Weisbecker wrote: > Hi Paul, > > 2013/1/5 Paul E. McKenney <paul...@linux.vnet.ibm.com>: > > From: Paul Gortmaker <paul.gortma...@windriver.com> > > > > The wait_event() at the head of the rcu_nocb_kthread() can result in > > soft-lockup complaints if the CPU in question does not register RCU > > callbacks for an extended period. This commit therefore changes > > the wait_event() to a wait_event_interruptible(). > > > > Reported-by: Frederic Weisbecker <fweis...@gmail.com> > > Signed-off-by: Paul Gortmaker <paul.gortma...@windriver.com> > > Signed-off-by: Paul E. McKenney <paul...@linux.vnet.ibm.com> > > --- > > kernel/rcutree_plugin.h | 3 ++- > > 1 files changed, 2 insertions(+), 1 deletions(-) > > > > diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h > > index f6e5ec2..43dba2d 100644 > > --- a/kernel/rcutree_plugin.h > > +++ b/kernel/rcutree_plugin.h > > @@ -2366,10 +2366,11 @@ static int rcu_nocb_kthread(void *arg) > > for (;;) { > > /* If not polling, wait for next batch of callbacks. */ > > if (!rcu_nocb_poll) > > - wait_event(rdp->nocb_wq, rdp->nocb_head); > > + wait_event_interruptible(rdp->nocb_wq, > > rdp->nocb_head); > > list = ACCESS_ONCE(rdp->nocb_head); > > if (!list) { > > schedule_timeout_interruptible(1); > > + flush_signals(current); > > Why is that needed?
To satisfy my paranoia. ;-) And in case someone ever figures out some way to send a signal to a kthread. Thanx, Paul -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/