[PATCH RT 16/30] sched: migrate disable: Protect cpus_ptr with lock
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2020-01-23 20:39:56
Also in:
lkml
Subsystem:
scheduler, the rest · Maintainers:
Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot, Linus Torvalds
4.19.94-rt39-rc2 stable review patch. If anyone has any objections, please let me know. ------------------ From: Scott Wood <redacted> [ 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: Steven Rostedt (VMware) <rostedt@goodmis.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 a29f33e776d0..d9a3f88508ee 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c@@ -7250,9 +7250,8 @@ 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);
@@ -7264,9 +7263,8 @@ 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);
--
2.24.1