X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=mm%2Fpage-writeback.c;h=3d3848fa6324ee30c8bfa4f39ac867808af84627;hb=3de5489f47febe0333b142e0eb6389b9924b2634;hp=7845462064f4c13457528852c09e5db9e770596b;hpb=2843483d2eb02ad104edbe8b2429fb6a39d25063;p=linux-2.6-omap-h63xx.git

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 7845462064f..3d3848fa632 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -297,20 +297,12 @@ get_dirty_limits(long *pbackground, long *pdirty, long *pbdi_dirty,
 {
 	int background_ratio;		/* Percentages */
 	int dirty_ratio;
-	int unmapped_ratio;
 	long background;
 	long dirty;
 	unsigned long available_memory = determine_dirtyable_memory();
 	struct task_struct *tsk;
 
-	unmapped_ratio = 100 - ((global_page_state(NR_FILE_MAPPED) +
-				global_page_state(NR_ANON_PAGES)) * 100) /
-					available_memory;
-
 	dirty_ratio = vm_dirty_ratio;
-	if (dirty_ratio > unmapped_ratio / 2)
-		dirty_ratio = unmapped_ratio / 2;
-
 	if (dirty_ratio < 5)
 		dirty_ratio = 5;
 
@@ -355,8 +347,8 @@ get_dirty_limits(long *pbackground, long *pdirty, long *pbdi_dirty,
  */
 static void balance_dirty_pages(struct address_space *mapping)
 {
-	long bdi_nr_reclaimable;
-	long bdi_nr_writeback;
+	long nr_reclaimable, bdi_nr_reclaimable;
+	long nr_writeback, bdi_nr_writeback;
 	long background_thresh;
 	long dirty_thresh;
 	long bdi_thresh;
@@ -376,11 +368,26 @@ static void balance_dirty_pages(struct address_space *mapping)
 
 		get_dirty_limits(&background_thresh, &dirty_thresh,
 				&bdi_thresh, bdi);
+
+		nr_reclaimable = global_page_state(NR_FILE_DIRTY) +
+					global_page_state(NR_UNSTABLE_NFS);
+		nr_writeback = global_page_state(NR_WRITEBACK);
+
 		bdi_nr_reclaimable = bdi_stat(bdi, BDI_RECLAIMABLE);
 		bdi_nr_writeback = bdi_stat(bdi, BDI_WRITEBACK);
+
 		if (bdi_nr_reclaimable + bdi_nr_writeback <= bdi_thresh)
 			break;
 
+		/*
+		 * Throttle it only when the background writeback cannot
+		 * catch-up. This avoids (excessively) small writeouts
+		 * when the bdi limits are ramping up.
+		 */
+		if (nr_reclaimable + nr_writeback <
+				(background_thresh + dirty_thresh) / 2)
+			break;
+
 		if (!bdi->dirty_exceeded)
 			bdi->dirty_exceeded = 1;
 
@@ -551,7 +558,6 @@ static void background_writeout(unsigned long _min_pages)
 			global_page_state(NR_UNSTABLE_NFS) < background_thresh
 				&& min_pages <= 0)
 			break;
-		wbc.more_io = 0;
 		wbc.encountered_congestion = 0;
 		wbc.nr_to_write = MAX_WRITEBACK_PAGES;
 		wbc.pages_skipped = 0;
@@ -559,9 +565,8 @@ static void background_writeout(unsigned long _min_pages)
 		min_pages -= MAX_WRITEBACK_PAGES - wbc.nr_to_write;
 		if (wbc.nr_to_write > 0 || wbc.pages_skipped > 0) {
 			/* Wrote less than expected */
-			if (wbc.encountered_congestion || wbc.more_io)
-				congestion_wait(WRITE, HZ/10);
-			else
+			congestion_wait(WRITE, HZ/10);
+			if (!wbc.encountered_congestion)
 				break;
 		}
 	}
@@ -626,12 +631,11 @@ static void wb_kupdate(unsigned long arg)
 			global_page_state(NR_UNSTABLE_NFS) +
 			(inodes_stat.nr_inodes - inodes_stat.nr_unused);
 	while (nr_to_write > 0) {
-		wbc.more_io = 0;
 		wbc.encountered_congestion = 0;
 		wbc.nr_to_write = MAX_WRITEBACK_PAGES;
 		writeback_inodes(&wbc);
 		if (wbc.nr_to_write > 0) {
-			if (wbc.encountered_congestion || wbc.more_io)
+			if (wbc.encountered_congestion)
 				congestion_wait(WRITE, HZ/10);
 			else
 				break;	/* All the old data is written */
@@ -989,7 +993,7 @@ int __set_page_dirty_no_writeback(struct page *page)
  * mapping is pinned by the vma's ->vm_file reference.
  *
  * We take care to handle the case where the page was truncated from the
- * mapping by re-checking page_mapping() insode tree_lock.
+ * mapping by re-checking page_mapping() inside tree_lock.
  */
 int __set_page_dirty_nobuffers(struct page *page)
 {