Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/juhl/trivial

[safe/jmp/linux-2.6] / mm / pdflush.c

diff --git a/mm/pdflush.c b/mm/pdflush.c
index d678195..1c96cfc 100644 (file)
--- a/mm/pdflush.c
+++ b/mm/pdflush.c
@@ -17,9 +17,11 @@
 #include <linux/gfp.h>
 #include <linux/init.h>
 #include <linux/module.h>
-#include <linux/fs.h>          // Needed by writeback.h
-#include <linux/writeback.h>   // Prototypes pdflush_operation()
+#include <linux/fs.h>          /* Needed by writeback.h          */
+#include <linux/writeback.h>   /* Prototypes pdflush_operation() */
 #include <linux/kthread.h>
+#include <linux/cpuset.h>
+#include <linux/freezer.h>
 
 
 /*
@@ -89,7 +91,8 @@ struct pdflush_work {
 
 static int __pdflush(struct pdflush_work *my_work)
 {
-       current->flags |= PF_FLUSHER;
+       current->flags |= PF_FLUSHER | PF_SWAPWRITE;
+       set_freezable();
        my_work->fn = NULL;
        my_work->who = current;
        INIT_LIST_HEAD(&my_work->list);
@@ -103,21 +106,20 @@ static int __pdflush(struct pdflush_work *my_work)
                list_move(&my_work->list, &pdflush_list);
                my_work->when_i_went_to_sleep = jiffies;
                spin_unlock_irq(&pdflush_lock);
-
                schedule();
-               if (try_to_freeze()) {
-                       spin_lock_irq(&pdflush_lock);
-                       continue;
-               }
-
+               try_to_freeze();
                spin_lock_irq(&pdflush_lock);
                if (!list_empty(&my_work->list)) {
-                       printk("pdflush: bogus wakeup!\n");
+                       /*
+                        * Someone woke us up, but without removing our control
+                        * structure from the global list.  swsusp will do this
+                        * in try_to_freeze()->refrigerator().  Handle it.
+                        */
                        my_work->fn = NULL;
                        continue;
                }
                if (my_work->fn == NULL) {
-                       printk("pdflush: NULL work function\n");
+                       printk("pdflush: bogus wakeup\n");
                        continue;
                }
                spin_unlock_irq(&pdflush_lock);
@@ -170,12 +172,24 @@ static int __pdflush(struct pdflush_work *my_work)
 static int pdflush(void *dummy)
 {
        struct pdflush_work my_work;
+       cpumask_t cpus_allowed;
 
        /*
         * pdflush can spend a lot of time doing encryption via dm-crypt.  We
         * don't want to do that at keventd's priority.
         */
        set_user_nice(current, 0);
+
+       /*
+        * Some configs put our parent kthread in a limited cpuset,
+        * which kthread() overrides, forcing cpus_allowed == CPU_MASK_ALL.
+        * Our needs are more modest - cut back to our cpusets cpus_allowed.
+        * This is needed as pdflush's are dynamically created and destroyed.
+        * The boottime pdflush's are easily placed w/o these 2 lines.
+        */
+       cpuset_cpus_allowed(current, &cpus_allowed);
+       set_cpus_allowed_ptr(current, &cpus_allowed);
+
        return __pdflush(&my_work);
 }
 
@@ -189,8 +203,7 @@ int pdflush_operation(void (*fn)(unsigned long), unsigned long arg0)
        unsigned long flags;
        int ret = 0;
 
-       if (fn == NULL)
-               BUG();          /* Hard to diagnose if it's deferred */
+       BUG_ON(fn == NULL);     /* Hard to diagnose if it's deferred */
 
        spin_lock_irqsave(&pdflush_lock, flags);
        if (list_empty(&pdflush_list)) {