mm: Add NR_WRITEBACK_TEMP counter
authorMiklos Szeredi <mszeredi@suse.cz>
Wed, 30 Apr 2008 07:54:38 +0000 (00:54 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 30 Apr 2008 15:29:50 +0000 (08:29 -0700)
commitfc3ba692a4d19019387c5acaea63131f9eab05dd
treec86e025cb8f79c7ffc479029989b7378bcb9f285
parentdd5656e59ca7b25fb60a22f9079905ed0da5ed0c
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>
drivers/base/node.c
fs/proc/proc_misc.c
include/linux/mmzone.h
mm/page-writeback.c
mm/vmstat.c