1 files changed, 25 insertions, 7 deletions

diff --git a/kernel/power/main.c b/kernel/power/main.c
index 4cdebc972ff2..71aa0fd22007 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -19,6 +19,9 @@
 
 #include "power.h"
 
+/*This is just an arbitrary number */
+#define FREE_PAGE_NUMBER (100)
+
 DECLARE_MUTEX(pm_sem);
 
 struct pm_ops * pm_ops = NULL;
@@ -49,17 +52,35 @@ void pm_set_ops(struct pm_ops * ops)
 static int suspend_prepare(suspend_state_t state)
 {
         int error = 0;
+        unsigned int free_pages;
 
         if (!pm_ops || !pm_ops->enter)
                 return -EPERM;
 
         pm_prepare_console();
 
+        disable_nonboot_cpus();
+
+        if (num_online_cpus() != 1) {
+                error = -EPERM;
+                goto Enable_cpu;
+        }
+
         if (freeze_processes()) {
                 error = -EAGAIN;
                 goto Thaw;
         }
 
+        if ((free_pages = nr_free_pages()) < FREE_PAGE_NUMBER) {
+                pr_debug("PM: free some memory\n");
+                shrink_all_memory(FREE_PAGE_NUMBER - free_pages);
+                if (nr_free_pages() < FREE_PAGE_NUMBER) {
+                        error = -ENOMEM;
+                        printk(KERN_ERR "PM: No enough memory\n");
+                        goto Thaw;
+                }
+        }
+
         if (pm_ops->prepare) {
                 if ((error = pm_ops->prepare(state)))
                         goto Thaw;
@@ -75,6 +96,8 @@ static int suspend_prepare(suspend_state_t state)
                 pm_ops->finish(state);
  Thaw:
         thaw_processes();
+ Enable_cpu:
+        enable_nonboot_cpus();
         pm_restore_console();
         return error;
 }
@@ -113,6 +136,7 @@ static void suspend_finish(suspend_state_t state)
         if (pm_ops && pm_ops->finish)
                 pm_ops->finish(state);
         thaw_processes();
+        enable_nonboot_cpus();
         pm_restore_console();
 }
 
@@ -150,12 +174,6 @@ static int enter_state(suspend_state_t state)
                 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;
@@ -190,7 +208,7 @@ int software_suspend(void)
 
 int pm_suspend(suspend_state_t state)
 {
-        if (state > PM_SUSPEND_ON && state < PM_SUSPEND_MAX)
+        if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
                 return enter_state(state);
         return -EINVAL;
 }