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| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-08-30 14:19:46 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-08-31 02:49:47 +0200 |
| commit | 942f40155a743f4204308d62405dacaa4bfadb11 (patch) | |
| tree | c65e934016413151824dcb6b15e0f2ae6ce1d23d | |
| parent | 8fd37a4c9822d58c93f764864582aa13112b1513 (diff) | |
| download | lwn-942f40155a743f4204308d62405dacaa4bfadb11.tar.gz lwn-942f40155a743f4204308d62405dacaa4bfadb11.zip | |
PM / hibernate / memory hotplug: Rework mutual exclusion
Since all of the memory hotplug operations have to be carried out
under device_hotplug_lock, they won't need to acquire pm_mutex if
device_hotplug_lock is held around hibernation.
For this reason, make the hibernation code acquire
device_hotplug_lock after freezing user space processes and
release it before thawing them. At the same tim drop the
lock_system_sleep() and unlock_system_sleep() calls from
lock_memory_hotplug() and unlock_memory_hotplug(), respectively.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
| -rw-r--r-- | kernel/power/hibernate.c | 4 | ||||
| -rw-r--r-- | kernel/power/user.c | 2 | ||||
| -rw-r--r-- | mm/memory_hotplug.c | 4 |
3 files changed, 6 insertions, 4 deletions
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index d4e54053d009..0b78f72ad39d 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -652,6 +652,7 @@ int hibernate(void) if (error) goto Exit; + lock_device_hotplug(); /* Allocate memory management structures */ error = create_basic_memory_bitmaps(); if (error) @@ -685,6 +686,7 @@ int hibernate(void) Free_bitmaps: free_basic_memory_bitmaps(); Thaw: + unlock_device_hotplug(); thaw_processes(); /* Don't bother checking whether freezer_test_done is true */ @@ -814,6 +816,7 @@ static int software_resume(void) pr_debug("PM: Loading hibernation image.\n"); + lock_device_hotplug(); error = create_basic_memory_bitmaps(); if (error) goto Thaw; @@ -827,6 +830,7 @@ static int software_resume(void) swsusp_free(); free_basic_memory_bitmaps(); Thaw: + unlock_device_hotplug(); thaw_processes(); Finish: pm_notifier_call_chain(PM_POST_RESTORE); diff --git a/kernel/power/user.c b/kernel/power/user.c index 63368163e98d..72e8f4fd616d 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -201,6 +201,7 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, if (!mutex_trylock(&pm_mutex)) return -EBUSY; + lock_device_hotplug(); data = filp->private_data; switch (cmd) { @@ -373,6 +374,7 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, } + unlock_device_hotplug(); mutex_unlock(&pm_mutex); return error; diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index ca1dd3aa5eee..53ad1325d7a7 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -51,14 +51,10 @@ DEFINE_MUTEX(mem_hotplug_mutex); void lock_memory_hotplug(void) { mutex_lock(&mem_hotplug_mutex); - - /* for exclusive hibernation if CONFIG_HIBERNATION=y */ - lock_system_sleep(); } void unlock_memory_hotplug(void) { - unlock_system_sleep(); mutex_unlock(&mem_hotplug_mutex); } |