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Merge tag 'pm-fix-for-3.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

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Power management fix for 3.3-rc2

Fix for a hibernate (s2disk) regression introduced during the 3.2
merge window that causes s2disk to trigger BUG_ON() in
freeze_workqueues_begin() if there is not enough swap space to save
the image.

* tag 'pm-fix-for-3.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM / Hibernate: Fix s2disk regression related to freezing workqueues
This commit is contained in:
Linus Torvalds
2012-01-30 08:33:40 -08:00
parent 0a96265754 181e9bdef3
commit a51f67a4b4
3 changed files with 30 additions and 0 deletions
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2
include/linux/freezer.h
View File

@@ -39,6 +39,7 @@ extern bool __refrigerator(bool check_kthr_stop);
extern int freeze_processes(void);
extern int freeze_kernel_threads(void);
extern void thaw_processes(void);
extern void thaw_kernel_threads(void);
static inline bool try_to_freeze(void)
{
@@ -174,6 +175,7 @@ static inline bool __refrigerator(bool check_kthr_stop) { return false; }
static inline int freeze_processes(void) { return -ENOSYS; }
static inline int freeze_kernel_threads(void) { return -ENOSYS; }
static inline void thaw_processes(void) {}
static inline void thaw_kernel_threads(void) {}
static inline bool try_to_freeze(void) { return false; }

19
kernel/power/process.c
View File

@@ -188,3 +188,22 @@ void thaw_processes(void)
printk("done.\n");
}
void thaw_kernel_threads(void)
{
struct task_struct *g, *p;
pm_nosig_freezing = false;
printk("Restarting kernel threads ... ");
thaw_workqueues();
read_lock(&tasklist_lock);
do_each_thread(g, p) {
if (p->flags & (PF_KTHREAD | PF_WQ_WORKER))
__thaw_task(p);
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
schedule();
printk("done.\n");
}

9
kernel/power/user.c
View File

@@ -274,6 +274,15 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
swsusp_free();
memset(&data->handle, 0, sizeof(struct snapshot_handle));
data->ready = 0;
/*
* It is necessary to thaw kernel threads here, because
* SNAPSHOT_CREATE_IMAGE may be invoked directly after
* SNAPSHOT_FREE. In that case, if kernel threads were not
* thawed, the preallocation of memory carried out by
* hibernation_snapshot() might run into problems (i.e. it
* might fail or even deadlock).
*/
thaw_kernel_threads();
break;
case SNAPSHOT_PREF_IMAGE_SIZE: