summaryrefslogtreecommitdiff
path: root/kernel/cpu.c
diff options
context:
space:
mode:
authorThomas Gleixner <tglx@linutronix.de>2023-10-17 21:40:46 +0200
committerThomas Gleixner <tglx@linutronix.de>2023-10-17 21:40:46 +0200
commita940daa52167e9db8ecce82213813b735a9d9f23 (patch)
treed5346c51351ccd1da7532cbec3127e6b73ec59c9 /kernel/cpu.c
parent32e4fa37fa667fdf53499b9de92737dc75199d8e (diff)
parent58720809f52779dc0f08e53e54b014209d13eebb (diff)
Merge branch 'linus' into smp/core
Pull in upstream to get the fixes so depending changes can be applied.
Diffstat (limited to 'kernel/cpu.c')
-rw-r--r--kernel/cpu.c24
1 files changed, 23 insertions, 1 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index f6811c857102..6de7c6bb74ee 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1487,8 +1487,22 @@ out:
return ret;
}
+struct cpu_down_work {
+ unsigned int cpu;
+ enum cpuhp_state target;
+};
+
+static long __cpu_down_maps_locked(void *arg)
+{
+ struct cpu_down_work *work = arg;
+
+ return _cpu_down(work->cpu, 0, work->target);
+}
+
static int cpu_down_maps_locked(unsigned int cpu, enum cpuhp_state target)
{
+ struct cpu_down_work work = { .cpu = cpu, .target = target, };
+
/*
* If the platform does not support hotplug, report it explicitly to
* differentiate it from a transient offlining failure.
@@ -1497,7 +1511,15 @@ static int cpu_down_maps_locked(unsigned int cpu, enum cpuhp_state target)
return -EOPNOTSUPP;
if (cpu_hotplug_disabled)
return -EBUSY;
- return _cpu_down(cpu, 0, target);
+
+ /*
+ * Ensure that the control task does not run on the to be offlined
+ * CPU to prevent a deadlock against cfs_b->period_timer.
+ */
+ cpu = cpumask_any_but(cpu_online_mask, cpu);
+ if (cpu >= nr_cpu_ids)
+ return -EBUSY;
+ return work_on_cpu(cpu, __cpu_down_maps_locked, &work);
}
static int cpu_down(unsigned int cpu, enum cpuhp_state target)