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authorMiklos Szeredi <mszeredi@suse.cz>2008-04-30 03:54:38 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-30 11:29:50 -0400
commitfc3ba692a4d19019387c5acaea63131f9eab05dd (patch)
treec86e025cb8f79c7ffc479029989b7378bcb9f285 /mm/page-writeback.c
parentdd5656e59ca7b25fb60a22f9079905ed0da5ed0c (diff)
mm: Add NR_WRITEBACK_TEMP counter
Fuse will use temporary buffers to write back dirty data from memory mappings (normal writes are done synchronously). This is needed, because there cannot be any guarantee about the time in which a write will complete. By using temporary buffers, from the MM's point if view the page is written back immediately. If the writeout was due to memory pressure, this effectively migrates data from a full zone to a less full zone. This patch adds a new counter (NR_WRITEBACK_TEMP) for the number of pages used as temporary buffers. [Lee.Schermerhorn@hp.com: add vmstat_text for NR_WRITEBACK_TEMP] Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page-writeback.c')
-rw-r--r--mm/page-writeback.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index c90a1e8e479f..789b6adbef37 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -211,7 +211,8 @@ clip_bdi_dirty_limit(struct backing_dev_info *bdi, long dirty, long *pbdi_dirty)
211 avail_dirty = dirty - 211 avail_dirty = dirty -
212 (global_page_state(NR_FILE_DIRTY) + 212 (global_page_state(NR_FILE_DIRTY) +
213 global_page_state(NR_WRITEBACK) + 213 global_page_state(NR_WRITEBACK) +
214 global_page_state(NR_UNSTABLE_NFS)); 214 global_page_state(NR_UNSTABLE_NFS) +
215 global_page_state(NR_WRITEBACK_TEMP));
215 216
216 if (avail_dirty < 0) 217 if (avail_dirty < 0)
217 avail_dirty = 0; 218 avail_dirty = 0;