]> git.openfabrics.org - ~shefty/rdma-dev.git/commitdiff
Merge tag 'pm-fix-for-3.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafae...
authorLinus Torvalds <torvalds@linux-foundation.org>
Mon, 30 Jan 2012 16:33:40 +0000 (08:33 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Mon, 30 Jan 2012 16:33:40 +0000 (08:33 -0800)
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

include/linux/freezer.h
kernel/power/process.c
kernel/power/user.c

index 0ab54e16a91f499b37db61fcd2be564232144a4a..d09af4b67cf121ad91fd4ca02bec01560b6110fd 100644 (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; }
 
index 77274c9ba2f1a95862787e041254f736539a1264..eeca00311f39568a7baa237364d58c3788d000cc 100644 (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");
+}
index 6b1ab7a88522827cc1ec5cdd3f0cdfa62d56accf..e5a21a857302e5e596e54eb3f8f6a00e8a342cae 100644 (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: