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authorMel Gorman <mgorman@suse.de>2011-10-31 17:07:59 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-10-31 17:30:47 -0700
commit49ea7eb65e7c5060807fb9312b1ad4c3eab82e2c (patch)
tree88eaa206cdcac1190817820a0eb56bca2585f9ea
parent92df3a723f84cdf8133560bbff950a7a99e92bc9 (diff)
downloadlinux-49ea7eb65e7c5060807fb9312b1ad4c3eab82e2c.tar.bz2
mm: vmscan: immediately reclaim end-of-LRU dirty pages when writeback completes
When direct reclaim encounters a dirty page, it gets recycled around the LRU for another cycle. This patch marks the page PageReclaim similar to deactivate_page() so that the page gets reclaimed almost immediately after the page gets cleaned. This is to avoid reclaiming clean pages that are younger than a dirty page encountered at the end of the LRU that might have been something like a use-once page. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Johannes Weiner <jweiner@redhat.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Alex Elder <aelder@sgi.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Chris Mason <chris.mason@oracle.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/mmzone.h2
-rw-r--r--mm/vmscan.c10
-rw-r--r--mm/vmstat.c2
3 files changed, 11 insertions, 3 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 2c41b2c1943b..188cb2ffe8db 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -100,7 +100,7 @@ enum zone_stat_item {
NR_UNSTABLE_NFS, /* NFS unstable pages */
NR_BOUNCE,
NR_VMSCAN_WRITE,
- NR_VMSCAN_WRITE_SKIP,
+ NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */
NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */
NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */
NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 7b0573f33a27..a297603d35bc 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -866,7 +866,15 @@ static unsigned long shrink_page_list(struct list_head *page_list,
*/
if (page_is_file_cache(page) &&
(!current_is_kswapd() || priority >= DEF_PRIORITY - 2)) {
- inc_zone_page_state(page, NR_VMSCAN_WRITE_SKIP);
+ /*
+ * Immediately reclaim when written back.
+ * Similar in principal to deactivate_page()
+ * except we already have the page isolated
+ * and know it's dirty
+ */
+ inc_zone_page_state(page, NR_VMSCAN_IMMEDIATE);
+ SetPageReclaim(page);
+
goto keep_locked;
}
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 210bd8ff3a6e..56e529a40517 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -702,7 +702,7 @@ const char * const vmstat_text[] = {
"nr_unstable",
"nr_bounce",
"nr_vmscan_write",
- "nr_vmscan_write_skip",
+ "nr_vmscan_immediate_reclaim",
"nr_writeback_temp",
"nr_isolated_anon",
"nr_isolated_file",