[PATCH] suspend/resume SMP support
Using CPU hotplug to support suspend/resume SMP. Both S3 and S4 use
disable/enable_nonboot_cpus API. The S4 part is based on Pavel's original S4
SMP patch.
Signed-off-by: Li Shaohua<shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 4cdebc9..c94cb9e 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -55,6 +55,13 @@
pm_prepare_console();
+ disable_nonboot_cpus();
+
+ if (num_online_cpus() != 1) {
+ error = -EPERM;
+ goto Enable_cpu;
+ }
+
if (freeze_processes()) {
error = -EAGAIN;
goto Thaw;
@@ -75,6 +82,8 @@
pm_ops->finish(state);
Thaw:
thaw_processes();
+ Enable_cpu:
+ enable_nonboot_cpus();
pm_restore_console();
return error;
}
@@ -113,6 +122,7 @@
if (pm_ops && pm_ops->finish)
pm_ops->finish(state);
thaw_processes();
+ enable_nonboot_cpus();
pm_restore_console();
}
@@ -150,12 +160,6 @@
goto Unlock;
}
- /* Suspend is hard to get right on SMP. */
- if (num_online_cpus() != 1) {
- error = -EPERM;
- goto Unlock;
- }
-
pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
if ((error = suspend_prepare(state)))
goto Unlock;