[PATCH] io-accounting: write accounting
Accounting writes is fairly simple: whenever a process flips a page from clean
to dirty, we accuse it of having caused a write to underlying storage of
PAGE_CACHE_SIZE bytes.
This may overestimate the amount of writing: the page-dirtying may cause only
one buffer_head's worth of writeout. Fixing that is possible, but probably a
bit messy and isn't obviously important.
Cc: Jay Lan <jlan@sgi.com>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Chris Sturtivant <csturtiv@sgi.com>
Cc: Tony Ernst <tee@sgi.com>
Cc: Guillaume Thouvenin <guillaume.thouvenin@bull.net>
Cc: David Wright <daw@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/buffer.c b/fs/buffer.c
index 865570f..904d59d 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -35,6 +35,7 @@
#include <linux/hash.h>
#include <linux/suspend.h>
#include <linux/buffer_head.h>
+#include <linux/task_io_accounting_ops.h>
#include <linux/bio.h>
#include <linux/notifier.h>
#include <linux/cpu.h>
@@ -729,8 +730,10 @@
write_lock_irq(&mapping->tree_lock);
if (page->mapping) { /* Race with truncate? */
- if (mapping_cap_account_dirty(mapping))
+ if (mapping_cap_account_dirty(mapping)) {
__inc_zone_page_state(page, NR_FILE_DIRTY);
+ task_io_account_write(PAGE_CACHE_SIZE);
+ }
radix_tree_tag_set(&mapping->page_tree,
page_index(page), PAGECACHE_TAG_DIRTY);
}