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authorLinus Torvalds <torvalds@linux-foundation.org>2013-08-02 12:21:32 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-08-02 12:21:32 -0700
commit1fe0135b9e135ecef4eb2144027a74c3de6bf874 (patch)
tree995bd5805ac6228a85d58eba69d6eeb0a54a5ead /kernel
parentMerge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux (diff)
parentfreezer: set PF_SUSPEND_TASK flag on tasks that call freeze_processes (diff)
downloadlinux-dev-1fe0135b9e135ecef4eb2144027a74c3de6bf874.tar.xz
linux-dev-1fe0135b9e135ecef4eb2144027a74c3de6bf874.zip
Merge tag 'pm+acpi-3.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI and power management fixes from Rafael Wysocki: - Revert two cpuidle commits added during the 3.8 development cycle that turn out to have introduced a significant performance regression as requested by Jeremy Eder. - The recent patches that made the freezer less heavy-weight introduced a regression causing user-space-driven hibernation using the ioctl() interface to block indefinitely when the hibernate process executes try_to_freeze(). Fix from Colin Cross addresses this by adding a process flag to mark the hibernate/suspend process to inform the freezer that that process should be ignored. - One of the recent cpufreq reverts uncovered a problem in the core causing the cpufreq driver module refcount to become negative after a system suspend-resume cycle. Fix from Rafael J Wysocki. - The evaluation of the ACPI battery _BIX method has never worked correctly, because the commit that added support for it forgot to take the "Revision" field in the return package into account. As a result, the reading of battery info doesn't work at all on some systems, which is addressed by a fix from Lan Tianyu. * tag 'pm+acpi-3.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: freezer: set PF_SUSPEND_TASK flag on tasks that call freeze_processes ACPI / battery: Fix parsing _BIX return value cpufreq: Fix cpufreq driver module refcount balance after suspend/resume Revert "cpuidle: Quickly notice prediction failure for repeat mode" Revert "cpuidle: Quickly notice prediction failure in general case"
Diffstat (limited to 'kernel')
-rw-r--r--kernel/freezer.c2
-rw-r--r--kernel/power/process.c11
-rw-r--r--kernel/time/tick-sched.c9
3 files changed, 14 insertions, 8 deletions
diff --git a/kernel/freezer.c b/kernel/freezer.c
index 8b2afc1c9df0..b462fa197517 100644
--- a/kernel/freezer.c
+++ b/kernel/freezer.c
@@ -33,7 +33,7 @@ static DEFINE_SPINLOCK(freezer_lock);
*/
bool freezing_slow_path(struct task_struct *p)
{
- if (p->flags & PF_NOFREEZE)
+ if (p->flags & (PF_NOFREEZE | PF_SUSPEND_TASK))
return false;
if (pm_nosig_freezing || cgroup_freezing(p))
diff --git a/kernel/power/process.c b/kernel/power/process.c
index fc0df8486449..06ec8869dbf1 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -109,6 +109,8 @@ static int try_to_freeze_tasks(bool user_only)
/**
* freeze_processes - Signal user space processes to enter the refrigerator.
+ * The current thread will not be frozen. The same process that calls
+ * freeze_processes must later call thaw_processes.
*
* On success, returns 0. On failure, -errno and system is fully thawed.
*/
@@ -120,6 +122,9 @@ int freeze_processes(void)
if (error)
return error;
+ /* Make sure this task doesn't get frozen */
+ current->flags |= PF_SUSPEND_TASK;
+
if (!pm_freezing)
atomic_inc(&system_freezing_cnt);
@@ -168,6 +173,7 @@ int freeze_kernel_threads(void)
void thaw_processes(void)
{
struct task_struct *g, *p;
+ struct task_struct *curr = current;
if (pm_freezing)
atomic_dec(&system_freezing_cnt);
@@ -182,10 +188,15 @@ void thaw_processes(void)
read_lock(&tasklist_lock);
do_each_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));
+ curr->flags &= ~PF_SUSPEND_TASK;
+
usermodehelper_enable();
schedule();
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index e80183f4a6c4..e77edc97e036 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -827,13 +827,10 @@ void tick_nohz_irq_exit(void)
{
struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
- if (ts->inidle) {
- /* Cancel the timer because CPU already waken up from the C-states*/
- menu_hrtimer_cancel();
+ if (ts->inidle)
__tick_nohz_idle_enter(ts);
- } else {
+ else
tick_nohz_full_stop_tick(ts);
- }
}
/**
@@ -931,8 +928,6 @@ void tick_nohz_idle_exit(void)
ts->inidle = 0;
- /* Cancel the timer because CPU already waken up from the C-states*/
- menu_hrtimer_cancel();
if (ts->idle_active || ts->tick_stopped)
now = ktime_get();