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author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2014-10-23 21:02:45 (GMT) |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2014-10-23 21:02:45 (GMT) |
commit | 96ed753235c674a8cb261dac1a258cf6e50c6cd4 (patch) | |
tree | f9210625db82644ebcf88d1879288b2fc389d211 /kernel | |
parent | 37c72cac0e2ef9cd3c53dc9369a35dad6ef23f00 (diff) | |
parent | 71be2114a5474a76edad95343d89b8731457fccd (diff) | |
download | linux-96ed753235c674a8cb261dac1a258cf6e50c6cd4.tar.xz |
Merge branch 'freezer'
* freezer:
PM / freezer: Clean up code after recent fixes
PM: convert do_each_thread to for_each_process_thread
OOM, PM: OOM killed task shouldn't escape PM suspend
freezer: remove obsolete comments in __thaw_task()
freezer: Do not freeze tasks killed by OOM killer
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/freezer.c | 9 | ||||
-rw-r--r-- | kernel/power/process.c | 57 |
2 files changed, 51 insertions, 15 deletions
diff --git a/kernel/freezer.c b/kernel/freezer.c index aa6a8aa..a8900a3 100644 --- a/kernel/freezer.c +++ b/kernel/freezer.c @@ -42,6 +42,9 @@ bool freezing_slow_path(struct task_struct *p) if (p->flags & (PF_NOFREEZE | PF_SUSPEND_TASK)) return false; + if (test_thread_flag(TIF_MEMDIE)) + return false; + if (pm_nosig_freezing || cgroup_freezing(p)) return true; @@ -147,12 +150,6 @@ void __thaw_task(struct task_struct *p) { unsigned long flags; - /* - * Clear freezing and kick @p if FROZEN. Clearing is guaranteed to - * be visible to @p as waking up implies wmb. Waking up inside - * freezer_lock also prevents wakeups from leaking outside - * refrigerator. - */ spin_lock_irqsave(&freezer_lock, flags); if (frozen(p)) wake_up_process(p); diff --git a/kernel/power/process.c b/kernel/power/process.c index 7b32322..5a6ec86 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -46,13 +46,13 @@ static int try_to_freeze_tasks(bool user_only) while (true) { todo = 0; read_lock(&tasklist_lock); - do_each_thread(g, p) { + for_each_process_thread(g, p) { if (p == current || !freeze_task(p)) continue; if (!freezer_should_skip(p)) todo++; - } while_each_thread(g, p); + } read_unlock(&tasklist_lock); if (!user_only) { @@ -93,11 +93,11 @@ static int try_to_freeze_tasks(bool user_only) if (!wakeup) { read_lock(&tasklist_lock); - do_each_thread(g, p) { + for_each_process_thread(g, p) { if (p != current && !freezer_should_skip(p) && freezing(p) && !frozen(p)) sched_show_task(p); - } while_each_thread(g, p); + } read_unlock(&tasklist_lock); } } else { @@ -108,6 +108,30 @@ static int try_to_freeze_tasks(bool user_only) return todo ? -EBUSY : 0; } +static bool __check_frozen_processes(void) +{ + struct task_struct *g, *p; + + for_each_process_thread(g, p) + if (p != current && !freezer_should_skip(p) && !frozen(p)) + return false; + + return true; +} + +/* + * Returns true if all freezable tasks (except for current) are frozen already + */ +static bool check_frozen_processes(void) +{ + bool ret; + + read_lock(&tasklist_lock); + ret = __check_frozen_processes(); + read_unlock(&tasklist_lock); + return ret; +} + /** * freeze_processes - Signal user space processes to enter the refrigerator. * The current thread will not be frozen. The same process that calls @@ -118,6 +142,7 @@ static int try_to_freeze_tasks(bool user_only) int freeze_processes(void) { int error; + int oom_kills_saved; error = __usermodehelper_disable(UMH_FREEZING); if (error) @@ -132,11 +157,25 @@ int freeze_processes(void) pm_wakeup_clear(); printk("Freezing user space processes ... "); pm_freezing = true; + oom_kills_saved = oom_kills_count(); error = try_to_freeze_tasks(true); if (!error) { - printk("done."); __usermodehelper_set_disable_depth(UMH_DISABLED); oom_killer_disable(); + + /* + * There might have been an OOM kill while we were + * freezing tasks and the killed task might be still + * on the way out so we have to double check for race. + */ + if (oom_kills_count() != oom_kills_saved && + !check_frozen_processes()) { + __usermodehelper_set_disable_depth(UMH_ENABLED); + printk("OOM in progress."); + error = -EBUSY; + } else { + printk("done."); + } } printk("\n"); BUG_ON(in_atomic()); @@ -191,11 +230,11 @@ void thaw_processes(void) thaw_workqueues(); read_lock(&tasklist_lock); - do_each_thread(g, p) { + for_each_process_thread(g, p) { /* No other threads should have PF_SUSPEND_TASK set */ WARN_ON((p != curr) && (p->flags & PF_SUSPEND_TASK)); __thaw_task(p); - } while_each_thread(g, p); + } read_unlock(&tasklist_lock); WARN_ON(!(curr->flags & PF_SUSPEND_TASK)); @@ -218,10 +257,10 @@ void thaw_kernel_threads(void) thaw_workqueues(); read_lock(&tasklist_lock); - do_each_thread(g, p) { + for_each_process_thread(g, p) { if (p->flags & (PF_KTHREAD | PF_WQ_WORKER)) __thaw_task(p); - } while_each_thread(g, p); + } read_unlock(&tasklist_lock); schedule(); |