X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=mm%2Fpage-writeback.c;h=624ce500fb169a8f3cc9f275fd26fc0f13dc3612;hb=6a77f38946aaee1cd85eeec6cf4229b204c15071;hp=343998d46bb03344d27845a79b6c20096e1508ca;hpb=9bf4aaab3e101692164d49b7ca357651eb691cb6;p=linux-2.6.git

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 343998d46..624ce500f 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -133,17 +133,29 @@ static void get_writeback_state(struct writeback_state *wbs)
  * clamping level.
  */
 static void
-get_dirty_limits(struct writeback_state *wbs, long *pbackground, long *pdirty)
+get_dirty_limits(struct writeback_state *wbs, long *pbackground, long *pdirty,
+		struct address_space *mapping)
 {
 	int background_ratio;		/* Percentages */
 	int dirty_ratio;
 	int unmapped_ratio;
 	long background;
 	long dirty;
+	unsigned long available_memory = total_pages;
 	struct task_struct *tsk;
 
 	get_writeback_state(wbs);
 
+#ifdef CONFIG_HIGHMEM
+	/*
+	 * If this mapping can only allocate from low memory,
+	 * we exclude high memory from our count.
+	 */
+	if (mapping && !(mapping_gfp_mask(mapping) & __GFP_HIGHMEM))
+		available_memory -= totalhigh_pages;
+#endif
+
+
 	unmapped_ratio = 100 - (wbs->nr_mapped * 100) / total_pages;
 
 	dirty_ratio = vm_dirty_ratio;
@@ -157,8 +169,8 @@ get_dirty_limits(struct writeback_state *wbs, long *pbackground, long *pdirty)
 	if (background_ratio >= dirty_ratio)
 		background_ratio = dirty_ratio / 2;
 
-	background = (background_ratio * total_pages) / 100;
-	dirty = (dirty_ratio * total_pages) / 100;
+	background = (background_ratio * available_memory) / 100;
+	dirty = (dirty_ratio * available_memory) / 100;
 	tsk = current;
 	if (tsk->flags & PF_LESS_THROTTLE || rt_task(tsk)) {
 		background += background / 4;
@@ -194,7 +206,8 @@ static void balance_dirty_pages(struct address_space *mapping)
 			.nr_to_write	= write_chunk,
 		};
 
-		get_dirty_limits(&wbs, &background_thresh, &dirty_thresh);
+		get_dirty_limits(&wbs, &background_thresh,
+					&dirty_thresh, mapping);
 		nr_reclaimable = wbs.nr_dirty + wbs.nr_unstable;
 		if (nr_reclaimable + wbs.nr_writeback <= dirty_thresh)
 			break;
@@ -210,7 +223,7 @@ static void balance_dirty_pages(struct address_space *mapping)
 		if (nr_reclaimable) {
 			writeback_inodes(&wbc);
 			get_dirty_limits(&wbs, &background_thresh,
-					&dirty_thresh);
+					&dirty_thresh, mapping);
 			nr_reclaimable = wbs.nr_dirty + wbs.nr_unstable;
 			if (nr_reclaimable + wbs.nr_writeback <= dirty_thresh)
 				break;
@@ -296,7 +309,7 @@ static void background_writeout(unsigned long _min_pages)
 		long background_thresh;
 		long dirty_thresh;
 
-		get_dirty_limits(&wbs, &background_thresh, &dirty_thresh);
+		get_dirty_limits(&wbs, &background_thresh, &dirty_thresh, NULL);
 		if (wbs.nr_dirty + wbs.nr_unstable < background_thresh
 				&& min_pages <= 0)
 			break;
@@ -504,6 +517,11 @@ void __init page_writeback_init(void)
 		dirty_background_ratio /= 100;
 		vm_dirty_ratio *= correction;
 		vm_dirty_ratio /= 100;
+
+		if (dirty_background_ratio <= 0)
+			dirty_background_ratio = 1;
+		if (vm_dirty_ratio <= 0)
+			vm_dirty_ratio = 1;
 	}
 	mod_timer(&wb_timer, jiffies + (dirty_writeback_centisecs * HZ) / 100);
 	set_ratelimit();
@@ -580,12 +598,13 @@ int __set_page_dirty_nobuffers(struct page *page)
 
 	if (!TestSetPageDirty(page)) {
 		struct address_space *mapping = page_mapping(page);
+		struct address_space *mapping2;
 
 		if (mapping) {
 			spin_lock_irq(&mapping->tree_lock);
-			mapping = page_mapping(page);
-			if (page_mapping(page)) { /* Race with truncate? */
-				BUG_ON(page_mapping(page) != mapping);
+			mapping2 = page_mapping(page);
+			if (mapping2) { /* Race with truncate? */
+				BUG_ON(mapping2 != mapping);
 				if (!mapping->backing_dev_info->memory_backed)
 					inc_page_state(nr_dirty);
 				radix_tree_tag_set(&mapping->page_tree,