diff options
| author | Alex Shi <alex.shi@linaro.org> | 2015-03-12 20:13:22 +0900 |
|---|---|---|
| committer | Seung-Woo Kim <sw0312.kim@samsung.com> | 2016-12-14 13:42:02 +0900 |
| commit | 7fbab276accd2f1b0f35c51ec03877b057042be3 (patch) | |
| tree | ab8afcd79965d2a31a6df6759866866d2586bd0d /kernel | |
| parent | 99b61b9a7433f8c1ee2713217dd454b3176e75f6 (diff) | |
HMP: use per cpu cpuidle driver to fix deadlock in hmp_idle_pull
Using per cpu cpuidle driver to fix deadlock in hmp_idle_pull.
Otherwise a deadlock happened when do bl_idle_init.
[ 113.878664] other info that might help us debug this:
[ 113.878667] Possible unsafe locking scenario:
[ 113.878667]
[ 113.878670] CPU0
[ 113.878673] ----
[ 113.878681] lock(cpuidle_driver_lock);
[ 113.878684] <Interrupt>
[ 113.878691] lock(cpuidle_driver_lock);
[ 113.878693]
[ 113.878693] *** DEADLOCK ***
[ 113.878693]
[ 113.878697] 1 lock held by ksoftirqd/4/28:
[ 113.878719] #0: (hmp_force_migration){+.....}, at: [<c0054da5>]
hmp_idle_pull+0x49/0x508
This patch is just a quick/cheap workaround for cpuidle_driver_lock
deadlock. It works for TC2 and any other platform where the idle
driver cannot be changed at runtime.
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Signed-off-by: Jon Medhurst <tixy@linaro.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/fair.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 33a6cdf9be0a..d5a39b1f3537 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5054,10 +5054,12 @@ static enum hrtimer_restart hmp_cpu_keepalive_notify(struct hrtimer *hrtimer) * If there are any, set ns_delay to * ('target_residency of state with shortest too-big latency' - 1) * 1000. */ -static void hmp_keepalive_delay(unsigned int *ns_delay) +static void hmp_keepalive_delay(int cpu, unsigned int *ns_delay) { + struct cpuidle_device *dev = per_cpu(cpuidle_devices, cpu); struct cpuidle_driver *drv; - drv = cpuidle_driver_ref(); + + drv = cpuidle_get_cpu_driver(dev); if (drv) { unsigned int us_delay = UINT_MAX; unsigned int us_max_delay = *ns_delay / 1000; @@ -5076,7 +5078,6 @@ static void hmp_keepalive_delay(unsigned int *ns_delay) else *ns_delay = 1000 * (us_delay - 1); } - cpuidle_driver_unref(); } static void hmp_cpu_keepalive_trigger(void) @@ -5090,7 +5091,7 @@ static void hmp_cpu_keepalive_trigger(void) CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED); keepalive->timer.function = hmp_cpu_keepalive_notify; - hmp_keepalive_delay(&ns_delay); + hmp_keepalive_delay(cpu, &ns_delay); keepalive->delay = ns_to_ktime(ns_delay); keepalive->init = true; } |