projects / thirdparty / kernel / stable-queue.git / blame
| Commit | Line | Data |
|---|---|---|
| 39f3dcdc SLM |
1 | From 1ed9b0ad863ec31da18bf386db2675a4d1db0e55 Mon Sep 17 00:00:00 2001 |
| 2 | From: Vitaly Kuznetsov <vkuznets@redhat.com> | |
| 3 | Date: Wed, 17 Oct 2018 13:23:55 +0200 | |
| 4 | Subject: kernel: hung_task.c: disable on suspend | |
| 5 | ||
| 6 | [ Upstream commit a1c6ca3c6de763459a6e93b644ec6518c890ba1c ] | |
| 7 | ||
| 8 | It is possible to observe hung_task complaints when system goes to | |
| 9 | suspend-to-idle state: | |
| 10 | ||
| 11 | # echo freeze > /sys/power/state | |
| 12 | ||
| 13 | PM: Syncing filesystems ... done. | |
| 14 | Freezing user space processes ... (elapsed 0.001 seconds) done. | |
| 15 | OOM killer disabled. | |
| 16 | Freezing remaining freezable tasks ... (elapsed 0.002 seconds) done. | |
| 17 | sd 0:0:0:0: [sda] Synchronizing SCSI cache | |
| 18 | INFO: task bash:1569 blocked for more than 120 seconds. | |
| 19 | Not tainted 4.19.0-rc3_+ #687 | |
| 20 | "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. | |
| 21 | bash D 0 1569 604 0x00000000 | |
| 22 | Call Trace: | |
| 23 | ? __schedule+0x1fe/0x7e0 | |
| 24 | schedule+0x28/0x80 | |
| 25 | suspend_devices_and_enter+0x4ac/0x750 | |
| 26 | pm_suspend+0x2c0/0x310 | |
| 27 | ||
| 28 | Register a PM notifier to disable the detector on suspend and re-enable | |
| 29 | back on wakeup. | |
| 30 | ||
| 31 | Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> | |
| 32 | Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> | |
| 33 | Signed-off-by: Sasha Levin <sashal@kernel.org> | |
| 34 | --- | |
| 35 | kernel/hung_task.c | 30 +++++++++++++++++++++++++++++- | |
| 36 | 1 file changed, 29 insertions(+), 1 deletion(-) | |
| 37 | ||
| 38 | diff --git a/kernel/hung_task.c b/kernel/hung_task.c | |
| 39 | index f9aaf4994062..2e4869fa66c9 100644 | |
| 40 | --- a/kernel/hung_task.c | |
| 41 | +++ b/kernel/hung_task.c | |
| 42 | @@ -15,6 +15,7 @@ | |
| 43 | #include <linux/lockdep.h> | |
| 44 | #include <linux/export.h> | |
| 45 | #include <linux/sysctl.h> | |
| 46 | +#include <linux/suspend.h> | |
| 47 | #include <linux/utsname.h> | |
| 48 | #include <linux/sched/signal.h> | |
| 49 | #include <linux/sched/debug.h> | |
| 50 | @@ -232,6 +233,28 @@ void reset_hung_task_detector(void) | |
| 51 | } | |
| 52 | EXPORT_SYMBOL_GPL(reset_hung_task_detector); | |
| 53 | ||
| 54 | +static bool hung_detector_suspended; | |
| 55 | + | |
| 56 | +static int hungtask_pm_notify(struct notifier_block *self, | |
| 57 | + unsigned long action, void *hcpu) | |
| 58 | +{ | |
| 59 | + switch (action) { | |
| 60 | + case PM_SUSPEND_PREPARE: | |
| 61 | + case PM_HIBERNATION_PREPARE: | |
| 62 | + case PM_RESTORE_PREPARE: | |
| 63 | + hung_detector_suspended = true; | |
| 64 | + break; | |
| 65 | + case PM_POST_SUSPEND: | |
| 66 | + case PM_POST_HIBERNATION: | |
| 67 | + case PM_POST_RESTORE: | |
| 68 | + hung_detector_suspended = false; | |
| 69 | + break; | |
| 70 | + default: | |
| 71 | + break; | |
| 72 | + } | |
| 73 | + return NOTIFY_OK; | |
| 74 | +} | |
| 75 | + | |
| 76 | /* | |
| 77 | * kthread which checks for tasks stuck in D state | |
| 78 | */ | |
| 79 | @@ -246,7 +269,8 @@ static int watchdog(void *dummy) | |
| 80 | long t = hung_timeout_jiffies(hung_last_checked, timeout); | |
| 81 | ||
| 82 | if (t <= 0) { | |
| 83 | - if (!atomic_xchg(&reset_hung_task, 0)) | |
| 84 | + if (!atomic_xchg(&reset_hung_task, 0) && | |
| 85 | + !hung_detector_suspended) | |
| 86 | check_hung_uninterruptible_tasks(timeout); | |
| 87 | hung_last_checked = jiffies; | |
| 88 | continue; | |
| 89 | @@ -260,6 +284,10 @@ static int watchdog(void *dummy) | |
| 90 | static int __init hung_task_init(void) | |
| 91 | { | |
| 92 | atomic_notifier_chain_register(&panic_notifier_list, &panic_block); | |
| 93 | + | |
| 94 | + /* Disable hung task detector on suspend */ | |
| 95 | + pm_notifier(hungtask_pm_notify, 0); | |
| 96 | + | |
| 97 | watchdog_task = kthread_run(watchdog, NULL, "khungtaskd"); | |
| 98 | ||
| 99 | return 0; | |
| 100 | -- | |
| 101 | 2.19.1 | |
| 102 |