diff mbox

[3/5] sched/preempt: cond_resched_softirq() must check for softirq

Message ID 5e046ef45554b053d22e76809a8faf546c3c0720.1465996447.git.pabeni@redhat.com
State Rejected, archived
Delegated to: David Miller
Headers show

Commit Message

Paolo Abeni June 15, 2016, 1:42 p.m. UTC 
Currently cond_resched_softirq() fails to reschedule if there
are pending softirq but no other running process. This happens
i.e. when receiving an interrupt with local bh disabled.

Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
---
 kernel/sched/core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Peter Zijlstra June 15, 2016, 1:48 p.m. UTC | #1 
On Wed, Jun 15, 2016 at 03:42:04PM +0200, Paolo Abeni wrote:
> Currently cond_resched_softirq() fails to reschedule if there
> are pending softirq but no other running process. This happens
> i.e. when receiving an interrupt with local bh disabled.
> 
> Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>

All your patches appear to have this broken SoB chain.

As presented it suggests you wrote the patches, which matches with From,
however it then suggests Hannes collected and send them onwards, not so
much.

Please correct.
Paolo Abeni June 15, 2016, 2 p.m. UTC | #2 
On Wed, 2016-06-15 at 15:48 +0200, Peter Zijlstra wrote:
> On Wed, Jun 15, 2016 at 03:42:04PM +0200, Paolo Abeni wrote:
> > Currently cond_resched_softirq() fails to reschedule if there
> > are pending softirq but no other running process. This happens
> > i.e. when receiving an interrupt with local bh disabled.
> > 
> > Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
> > Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> > Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
> 
> All your patches appear to have this broken SoB chain.
> 
> As presented it suggests you wrote the patches, which matches with From,
> however it then suggests Hannes collected and send them onwards, not so
> much.
> 
> Please correct.

My bad. I'll re-submit. The intention was to specify this is joint work
done together with Hannes.

Paolo
diff mbox

Patch

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 7f2cae4..788625f 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4837,7 +4837,8 @@  int __sched __cond_resched_softirq(void)
 {
 	BUG_ON(!in_softirq());
 
-	if (should_resched(SOFTIRQ_DISABLE_OFFSET)) {
+	if (should_resched(SOFTIRQ_DISABLE_OFFSET) ||
+	    local_softirq_pending()) {
 		local_bh_enable();
 		preempt_schedule_common();
 		local_bh_disable();