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authorRafael J. Wysocki <rjw@sisk.pl>2011-11-23 21:09:02 +0100
committerRafael J. Wysocki <rjw@sisk.pl>2011-11-23 21:09:02 +0100
commit986b11c3ee9e0eace25fe74a502205f7fe8c179b (patch)
tree2271bc519eac458fd92799f5731e2ef604f69341 /kernel/power
parentbb58dd5d1ffad6c2d21c69698ba766dad4ae54e6 (diff)
parent24b7ead3fb0bae267c2ee50898eb4c13aedd1e9f (diff)
Merge branch 'pm-freezer' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc into pm-freezer
* 'pm-freezer' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc: (24 commits) freezer: fix wait_event_freezable/__thaw_task races freezer: kill unused set_freezable_with_signal() dmatest: don't use set_freezable_with_signal() usb_storage: don't use set_freezable_with_signal() freezer: remove unused @sig_only from freeze_task() freezer: use lock_task_sighand() in fake_signal_wake_up() freezer: restructure __refrigerator() freezer: fix set_freezable[_with_signal]() race freezer: remove should_send_signal() and update frozen() freezer: remove now unused TIF_FREEZE freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE cgroup_freezer: prepare for removal of TIF_FREEZE freezer: clean up freeze_processes() failure path freezer: kill PF_FREEZING freezer: test freezable conditions while holding freezer_lock freezer: make freezing indicate freeze condition in effect freezer: use dedicated lock instead of task_lock() + memory barrier freezer: don't distinguish nosig tasks on thaw freezer: remove racy clear_freeze_flag() and set PF_NOFREEZE on dead tasks freezer: rename thaw_process() to __thaw_task() and simplify the implementation ...
Diffstat (limited to 'kernel/power')
-rw-r--r--kernel/power/hibernate.c15
-rw-r--r--kernel/power/process.c77
-rw-r--r--kernel/power/suspend.c8
-rw-r--r--kernel/power/user.c4
4 files changed, 37 insertions, 67 deletions
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index a6b0503574e..e7ffa895208 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -611,17 +611,6 @@ static void power_down(void)
while(1);
}
-static int prepare_processes(void)
-{
- int error = 0;
-
- if (freeze_processes()) {
- error = -EBUSY;
- thaw_processes();
- }
- return error;
-}
-
/**
* hibernate - Carry out system hibernation, including saving the image.
*/
@@ -654,7 +643,7 @@ int hibernate(void)
sys_sync();
printk("done.\n");
- error = prepare_processes();
+ error = freeze_processes();
if (error)
goto Finish;
@@ -815,7 +804,7 @@ static int software_resume(void)
goto close_finish;
pr_debug("PM: Preparing processes for restore.\n");
- error = prepare_processes();
+ error = freeze_processes();
if (error) {
swsusp_close(FMODE_READ);
goto Done;
diff --git a/kernel/power/process.c b/kernel/power/process.c
index addbbe5531b..77274c9ba2f 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -22,16 +22,7 @@
*/
#define TIMEOUT (20 * HZ)
-static inline int freezable(struct task_struct * p)
-{
- if ((p == current) ||
- (p->flags & PF_NOFREEZE) ||
- (p->exit_state != 0))
- return 0;
- return 1;
-}
-
-static int try_to_freeze_tasks(bool sig_only)
+static int try_to_freeze_tasks(bool user_only)
{
struct task_struct *g, *p;
unsigned long end_time;
@@ -46,17 +37,14 @@ static int try_to_freeze_tasks(bool sig_only)
end_time = jiffies + TIMEOUT;
- if (!sig_only)
+ if (!user_only)
freeze_workqueues_begin();
while (true) {
todo = 0;
read_lock(&tasklist_lock);
do_each_thread(g, p) {
- if (frozen(p) || !freezable(p))
- continue;
-
- if (!freeze_task(p, sig_only))
+ if (p == current || !freeze_task(p))
continue;
/*
@@ -77,7 +65,7 @@ static int try_to_freeze_tasks(bool sig_only)
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
- if (!sig_only) {
+ if (!user_only) {
wq_busy = freeze_workqueues_busy();
todo += wq_busy;
}
@@ -103,11 +91,6 @@ static int try_to_freeze_tasks(bool sig_only)
elapsed_csecs = elapsed_csecs64;
if (todo) {
- /* This does not unfreeze processes that are already frozen
- * (we have slightly ugly calling convention in that respect,
- * and caller must call thaw_processes() if something fails),
- * but it cleans up leftover PF_FREEZE requests.
- */
printk("\n");
printk(KERN_ERR "Freezing of tasks %s after %d.%02d seconds "
"(%d tasks refusing to freeze, wq_busy=%d):\n",
@@ -115,15 +98,11 @@ static int try_to_freeze_tasks(bool sig_only)
elapsed_csecs / 100, elapsed_csecs % 100,
todo - wq_busy, wq_busy);
- thaw_workqueues();
-
read_lock(&tasklist_lock);
do_each_thread(g, p) {
- task_lock(p);
- if (!wakeup && freezing(p) && !freezer_should_skip(p))
+ if (!wakeup && !freezer_should_skip(p) &&
+ p != current && freezing(p) && !frozen(p))
sched_show_task(p);
- cancel_freezing(p);
- task_unlock(p);
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
} else {
@@ -136,12 +115,18 @@ static int try_to_freeze_tasks(bool sig_only)
/**
* freeze_processes - Signal user space processes to enter the refrigerator.
+ *
+ * On success, returns 0. On failure, -errno and system is fully thawed.
*/
int freeze_processes(void)
{
int error;
+ if (!pm_freezing)
+ atomic_inc(&system_freezing_cnt);
+
printk("Freezing user space processes ... ");
+ pm_freezing = true;
error = try_to_freeze_tasks(true);
if (!error) {
printk("done.");
@@ -150,17 +135,22 @@ int freeze_processes(void)
printk("\n");
BUG_ON(in_atomic());
+ if (error)
+ thaw_processes();
return error;
}
/**
* freeze_kernel_threads - Make freezable kernel threads go to the refrigerator.
+ *
+ * On success, returns 0. On failure, -errno and system is fully thawed.
*/
int freeze_kernel_threads(void)
{
int error;
printk("Freezing remaining freezable tasks ... ");
+ pm_nosig_freezing = true;
error = try_to_freeze_tasks(false);
if (!error)
printk("done.");
@@ -168,37 +158,32 @@ int freeze_kernel_threads(void)
printk("\n");
BUG_ON(in_atomic());
+ if (error)
+ thaw_processes();
return error;
}
-static void thaw_tasks(bool nosig_only)
+void thaw_processes(void)
{
struct task_struct *g, *p;
- read_lock(&tasklist_lock);
- do_each_thread(g, p) {
- if (!freezable(p))
- continue;
+ if (pm_freezing)
+ atomic_dec(&system_freezing_cnt);
+ pm_freezing = false;
+ pm_nosig_freezing = false;
- if (nosig_only && should_send_signal(p))
- continue;
+ oom_killer_enable();
+
+ printk("Restarting tasks ... ");
- if (cgroup_freezing_or_frozen(p))
- continue;
+ thaw_workqueues();
- thaw_process(p);
+ read_lock(&tasklist_lock);
+ do_each_thread(g, p) {
+ __thaw_task(p);
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
-}
-void thaw_processes(void)
-{
- oom_killer_enable();
-
- printk("Restarting tasks ... ");
- thaw_workqueues();
- thaw_tasks(true);
- thaw_tasks(false);
schedule();
printk("done.\n");
}
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 4953dc054c5..d336b27d110 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -106,13 +106,11 @@ static int suspend_prepare(void)
goto Finish;
error = suspend_freeze_processes();
- if (error) {
- suspend_stats.failed_freeze++;
- dpm_save_failed_step(SUSPEND_FREEZE);
- } else
+ if (!error)
return 0;
- suspend_thaw_processes();
+ suspend_stats.failed_freeze++;
+ dpm_save_failed_step(SUSPEND_FREEZE);
usermodehelper_enable();
Finish:
pm_notifier_call_chain(PM_POST_SUSPEND);
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 6d8f535c2b8..7cc3f5bc5c2 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -257,10 +257,8 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
break;
error = freeze_processes();
- if (error) {
- thaw_processes();
+ if (error)
usermodehelper_enable();
- }
if (!error)
data->frozen = 1;
break;