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[v3,09/13] task_isolation: don't interrupt CPUs with tick_nohz_full_kick_cpu()

Message ID eb1f4ecbda4aa49a23bc459a37b8f160828f2919.camel@marvell.com
State Superseded
Headers show
Series [01/13] task_isolation: vmstat: add quiet_vmstat_sync function | expand

Commit Message

Alex Belits April 9, 2020, 3:25 p.m. UTC 
From: Yuri Norov <ynorov@marvell.com>


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 <ynorov@marvell.com>

[abelits@marvell.com: updated, only exclude CPUs running isolated tasks]
Signed-off-by: Alex Belits <abelits@marvell.com>

---
 kernel/time/tick-sched.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

-- 
2.20.1
diff mbox series

Patch

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 1d4dec9d3ee7..8488c2825a45 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>
@@ -262,7 +263,8 @@  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);