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

From: Paolo Abeni
Date: Wed Jun 15 2016 - 09:43:43 EST


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@xxxxxxxxx>
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Hannes Frederic Sowa <hannes@xxxxxxxxxxxxxxxxxxx>
---
kernel/sched/core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

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();
--
1.8.3.1