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authorAlex Shi <alex.shi@linaro.org>2014-06-19 13:47:35 +0800
committerJon Medhurst <tixy@linaro.org>2014-06-27 10:18:30 +0100
commit65abdc9b50378783981ed2f3453a0aae090404e4 (patch)
treea4d9a71b370c2904be7396a11784ae38860f07f8
parent4378062f289e67259f017f6b176ee385dc974836 (diff)
downloadmp-65abdc9b50378783981ed2f3453a0aae090404e4.tar.gz
HMP: use per cpu cpuidle driver to fix deadlock in hmp_idle_pullbig-LITTLE-MP-14.07
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>
-rw-r--r--kernel/sched/fair.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 26c43b4..161da1a 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3560,10 +3560,12 @@ 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;
@@ -3582,7 +3584,6 @@ 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)
@@ -3596,7 +3597,7 @@ 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;
}