mm: allow memory hotplug and hibernation in the same kernel
Allow memory hotplug and hibernation in the same kernel
Memory hotplug and hibernation were exclusive in Kconfig. This is
obviously a problem for distribution kernels who want to support both in
the same image.
After some discussions with Rafael and others the only problem is with
parallel memory hotadd or removal while a hibernation operation is in
process. It was also working for s390 before.
This patch removes the Kconfig level exclusion, and simply makes the
memory add / remove functions grab the pm_mutex to exclude against
hibernation.
Fixes a regression - old kernels didn't exclude memory hotadd and
hibernation.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index cd15df6..5e781d8 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -301,6 +301,8 @@
#define pm_notifier(fn, pri) do { (void)(fn); } while (0)
#endif /* !CONFIG_PM_SLEEP */
+extern struct mutex pm_mutex;
+
#ifndef CONFIG_HIBERNATION
static inline void register_nosave_region(unsigned long b, unsigned long e)
{
@@ -308,8 +310,23 @@
static inline void register_nosave_region_late(unsigned long b, unsigned long e)
{
}
-#endif
-extern struct mutex pm_mutex;
+static inline void lock_system_sleep(void) {}
+static inline void unlock_system_sleep(void) {}
+
+#else
+
+/* Let some subsystems like memory hotadd exclude hibernation */
+
+static inline void lock_system_sleep(void)
+{
+ mutex_lock(&pm_mutex);
+}
+
+static inline void unlock_system_sleep(void)
+{
+ mutex_unlock(&pm_mutex);
+}
+#endif
#endif /* _LINUX_SUSPEND_H */