[PATCH v4 10/13] task_isolation: don't interrupt CPUs with tick_nohz_full_kick_cpu()

From
Alex Belits <hidden>
Date
2020-07-22 14:58:04
Also in
linux-arch, linux-arm-kernel, lkml, netdev
Reply to
Alex Belits, 2020-07-22
From: Yuri Norov <redacted>

For nohz_full CPUs the desirable behavior is to receive interrupts
generated by tick_nohz_full_kick_cpu(). But for hard isolation it's
obviously not desirable because it breaks isolation.

This patch adds check for it.

Signed-off-by: Yuri Norov <redacted>
[abelits@marvell.com: updated, only exclude CPUs running isolated tasks]
Signed-off-by: Alex Belits <redacted>
---
 kernel/time/tick-sched.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 6e4cd8459f05..2f82a6daf8fc 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -20,6 +20,7 @@
 #include <linux/sched/clock.h>
 #include <linux/sched/stat.h>
 #include <linux/sched/nohz.h>
+#include <linux/isolation.h>
 #include <linux/module.h>
 #include <linux/irq_work.h>
 #include <linux/posix-timers.h>
@@ -268,7 +269,8 @@ static void tick_nohz_full_kick(void)
  */
 void tick_nohz_full_kick_cpu(int cpu)
 {
-	if (!tick_nohz_full_cpu(cpu))
+	smp_rmb();
+	if (!tick_nohz_full_cpu(cpu) || task_isolation_on_cpu(cpu))
 		return;
 
 	irq_work_queue_on(&per_cpu(nohz_full_kick_work, cpu), cpu);
-- 
2.26.2
Thread (49 messages) 49 messages, 7 authors, last reply 2021-01-22
Keyboard shortcuts
hback out one level
jnext message in thread / next series-diff position
kprevious message in thread / previous series-diff position
ldrill in
Escclose help / fold thread tree
?toggle this help