X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;ds=sidebyside;f=mm%2Fpage-writeback.c;h=029dfad5a235753fab2b7f81dda1950e770e9f2d;hb=ef93127e4c7b4b8d46421045641048397eaac43d;hp=f7e088f5a309eff3a03c8da5ad4ca4b37ecd5518;hpb=f8abea8f8c24ecdad6d6861bffb912f23f2741cd;p=powerpc.git

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index f7e088f5a3..029dfad5a2 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -67,12 +67,12 @@ static inline long sync_writeback_pages(void)
 /*
  * Start background writeback (via pdflush) at this percentage
  */
-int dirty_background_ratio = 10;
+int dirty_background_ratio = 5;
 
 /*
  * The generator of dirty data starts writeback at this percentage
  */
-int vm_dirty_ratio = 40;
+int vm_dirty_ratio = 10;
 
 /*
  * The interval between `kupdate'-style writebacks, in jiffies
@@ -119,6 +119,44 @@ static void background_writeout(unsigned long _min_pages);
  * We make sure that the background writeout level is below the adjusted
  * clamping level.
  */
+
+static unsigned long highmem_dirtyable_memory(unsigned long total)
+{
+#ifdef CONFIG_HIGHMEM
+	int node;
+	unsigned long x = 0;
+
+	for_each_online_node(node) {
+		struct zone *z =
+			&NODE_DATA(node)->node_zones[ZONE_HIGHMEM];
+
+		x += zone_page_state(z, NR_FREE_PAGES)
+			+ zone_page_state(z, NR_INACTIVE)
+			+ zone_page_state(z, NR_ACTIVE);
+	}
+	/*
+	 * Make sure that the number of highmem pages is never larger
+	 * than the number of the total dirtyable memory. This can only
+	 * occur in very strange VM situations but we want to make sure
+	 * that this does not occur.
+	 */
+	return min(x, total);
+#else
+	return 0;
+#endif
+}
+
+static unsigned long determine_dirtyable_memory(void)
+{
+	unsigned long x;
+
+	x = global_page_state(NR_FREE_PAGES)
+		+ global_page_state(NR_INACTIVE)
+		+ global_page_state(NR_ACTIVE);
+	x -= highmem_dirtyable_memory(x);
+	return x + 1;	/* Ensure that we never return 0 */
+}
+
 static void
 get_dirty_limits(long *pbackground, long *pdirty,
 					struct address_space *mapping)
@@ -128,20 +166,12 @@ get_dirty_limits(long *pbackground, long *pdirty,
 	int unmapped_ratio;
 	long background;
 	long dirty;
-	unsigned long available_memory = vm_total_pages;
+	unsigned long available_memory = determine_dirtyable_memory();
 	struct task_struct *tsk;
 
-#ifdef CONFIG_HIGHMEM
-	/*
-	 * We always exclude high memory from our count.
-	 */
-	available_memory -= totalhigh_pages;
-#endif
-
-
 	unmapped_ratio = 100 - ((global_page_state(NR_FILE_MAPPED) +
 				global_page_state(NR_ANON_PAGES)) * 100) /
-					vm_total_pages;
+					available_memory;
 
 	dirty_ratio = vm_dirty_ratio;
 	if (dirty_ratio > unmapped_ratio / 2)
@@ -296,11 +326,21 @@ void balance_dirty_pages_ratelimited_nr(struct address_space *mapping,
 }
 EXPORT_SYMBOL(balance_dirty_pages_ratelimited_nr);
 
-void throttle_vm_writeout(void)
+void throttle_vm_writeout(gfp_t gfp_mask)
 {
 	long background_thresh;
 	long dirty_thresh;
 
+	if ((gfp_mask & (__GFP_FS|__GFP_IO)) != (__GFP_FS|__GFP_IO)) {
+		/*
+		 * The caller might hold locks which can prevent IO completion
+		 * or progress in the filesystem.  So we cannot just sit here
+		 * waiting for IO to complete.
+		 */
+		congestion_wait(WRITE, HZ/10);
+		return;
+	}
+
         for ( ; ; ) {
 		get_dirty_limits(&background_thresh, &dirty_thresh, NULL);
 
@@ -317,7 +357,6 @@ void throttle_vm_writeout(void)
         }
 }
 
-
 /*
  * writeback at least _min_pages, and keep writing until the amount of dirty
  * memory is less than the background threshold, or until we're all clean.