Merge branch 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuil...

[pandora-kernel.git] / include / linux / compaction.h

diff --git a/include/linux/compaction.h b/include/linux/compaction.h
index eed40ec..5ac5155 100644 (file)
--- a/include/linux/compaction.h
+++ b/include/linux/compaction.h
@@ -15,10 +15,43 @@
 extern int sysctl_compact_memory;
 extern int sysctl_compaction_handler(struct ctl_table *table, int write,
                        void __user *buffer, size_t *length, loff_t *ppos);
+extern int sysctl_extfrag_threshold;
+extern int sysctl_extfrag_handler(struct ctl_table *table, int write,
+                       void __user *buffer, size_t *length, loff_t *ppos);
 
 extern int fragmentation_index(struct zone *zone, unsigned int order);
 extern unsigned long try_to_compact_pages(struct zonelist *zonelist,
                        int order, gfp_t gfp_mask, nodemask_t *mask);
+
+/* Do not skip compaction more than 64 times */
+#define COMPACT_MAX_DEFER_SHIFT 6
+
+/*
+ * Compaction is deferred when compaction fails to result in a page
+ * allocation success. 1 << compact_defer_limit compactions are skipped up
+ * to a limit of 1 << COMPACT_MAX_DEFER_SHIFT
+ */
+static inline void defer_compaction(struct zone *zone)
+{
+       zone->compact_considered = 0;
+       zone->compact_defer_shift++;
+
+       if (zone->compact_defer_shift > COMPACT_MAX_DEFER_SHIFT)
+               zone->compact_defer_shift = COMPACT_MAX_DEFER_SHIFT;
+}
+
+/* Returns true if compaction should be skipped this time */
+static inline bool compaction_deferred(struct zone *zone)
+{
+       unsigned long defer_limit = 1UL << zone->compact_defer_shift;
+
+       /* Avoid possible overflow */
+       if (++zone->compact_considered > defer_limit)
+               zone->compact_considered = defer_limit;
+
+       return zone->compact_considered < (1UL << zone->compact_defer_shift);
+}
+
 #else
 static inline unsigned long try_to_compact_pages(struct zonelist *zonelist,
                        int order, gfp_t gfp_mask, nodemask_t *nodemask)
@@ -26,6 +59,15 @@ static inline unsigned long try_to_compact_pages(struct zonelist *zonelist,
        return COMPACT_CONTINUE;
 }
 
+static inline void defer_compaction(struct zone *zone)
+{
+}
+
+static inline bool compaction_deferred(struct zone *zone)
+{
+       return 1;
+}
+
 #endif /* CONFIG_COMPACTION */
 
 #if defined(CONFIG_COMPACTION) && defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)