[PATCH 13/13] task_isolation: kick_all_cpus_sync: don't kick isolated cpus

From: Alex Belits
Date: Wed Jul 22 2020 - 11:00:27 EST


From: Yuri Norov <ynorov@xxxxxxxxxxx>

Make sure that kick_all_cpus_sync() does not call CPUs that are running
isolated tasks.

Signed-off-by: Yuri Norov <ynorov@xxxxxxxxxxx>
[abelits@xxxxxxxxxxx: use safe task_isolation_cpumask() implementation]
Signed-off-by: Alex Belits <abelits@xxxxxxxxxxx>
---
kernel/smp.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/kernel/smp.c b/kernel/smp.c
index 6a6849783948..ff0d95db33b3 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -803,9 +803,21 @@ static void do_nothing(void *unused)
*/
void kick_all_cpus_sync(void)
{
+ struct cpumask mask;
+
/* Make sure the change is visible before we kick the cpus */
smp_mb();
- smp_call_function(do_nothing, NULL, 1);
+
+ preempt_disable();
+#ifdef CONFIG_TASK_ISOLATION
+ cpumask_clear(&mask);
+ task_isolation_cpumask(&mask);
+ cpumask_complement(&mask, &mask);
+#else
+ cpumask_setall(&mask);
+#endif
+ smp_call_function_many(&mask, do_nothing, NULL, 1);
+ preempt_enable();
}
EXPORT_SYMBOL_GPL(kick_all_cpus_sync);

--
2.26.2