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authorLinus Torvalds <torvalds@linux-foundation.org>2012-01-30 08:33:40 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-01-30 08:33:40 -0800
commita51f67a4b440896dfc170ff3ce35994771b1267f (patch)
tree66e69f83b63e8517a47e0eb0e7ae730d8a9a109b
parent0a9626575400879d1d5e6bc8768188b938d7c501 (diff)
parent181e9bdef37bfcaa41f3ab6c948a2a0d60a268b5 (diff)
downloadlinux-linaro-stable-a51f67a4b440896dfc170ff3ce35994771b1267f.tar.gz
Merge tag 'pm-fix-for-3.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
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
-rw-r--r--include/linux/freezer.h2
-rw-r--r--kernel/power/process.c19
-rw-r--r--kernel/power/user.c9
3 files changed, 30 insertions, 0 deletions
diff --git a/include/linux/freezer.h b/include/linux/freezer.h
index 0ab54e16a91f..d09af4b67cf1 100644
--- a/include/linux/freezer.h
+++ b/include/linux/freezer.h
@@ -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; }
diff --git a/kernel/power/process.c b/kernel/power/process.c
index 77274c9ba2f1..eeca00311f39 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -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");
+}
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 6b1ab7a88522..e5a21a857302 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -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: