[PATCH RT 09/25] sched: migrate disable: Protect cpus_ptr with lock
From: zanussi@kernel.org
Date: 2020-02-21 21:25:30
Also in:
lkml
Subsystem:
scheduler, the rest · Maintainers:
Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot, Linus Torvalds
From: Scott Wood <redacted> v4.14.170-rt75-rc1 stable review patch. If anyone has any objections, please let me know. ----------- [ Upstream commit 27ee52a891ed2c7e2e2c8332ccae0de7c2674b09 ] Various places assume that cpus_ptr is protected by rq/pi locks, so don't change it before grabbing those locks. Signed-off-by: Scott Wood <redacted> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Tom Zanussi <zanussi@kernel.org> --- kernel/sched/core.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 4708129e8df1..189e6f08575e 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c@@ -6923,9 +6923,8 @@ migrate_disable_update_cpus_allowed(struct task_struct *p) struct rq *rq; struct rq_flags rf; - p->cpus_ptr = cpumask_of(smp_processor_id()); - rq = task_rq_lock(p, &rf); + p->cpus_ptr = cpumask_of(smp_processor_id()); update_nr_migratory(p, -1); p->nr_cpus_allowed = 1; task_rq_unlock(rq, p, &rf);
@@ -6937,9 +6936,8 @@ migrate_enable_update_cpus_allowed(struct task_struct *p) struct rq *rq; struct rq_flags rf; - p->cpus_ptr = &p->cpus_mask; - rq = task_rq_lock(p, &rf); + p->cpus_ptr = &p->cpus_mask; p->nr_cpus_allowed = cpumask_weight(&p->cpus_mask); update_nr_migratory(p, 1); task_rq_unlock(rq, p, &rf);
--
2.14.1