Commit 1cf6e7d8 authored by Nick Piggin's avatar Nick Piggin Committed by Linus Torvalds
Browse files

mm: task dirty accounting fix 



YAMAMOTO-san noticed that task_dirty_inc doesn't seem to be called properly for
cases where set_page_dirty is not used to dirty a page (eg. mark_buffer_dirty).

Additionally, there is some inconsistency about when task_dirty_inc is
called.  It is used for dirty balancing, however it even gets called for
__set_page_dirty_no_writeback.

So rather than increment it in a set_page_dirty wrapper, move it down to
exactly where the dirty page accounting stats are incremented.

Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 610d18f4

fs/buffer.c

+1 −0
Original line number Diff line number Diff line
@@ -777,6 +777,7 @@ static int __set_page_dirty(struct page *page, 
			__inc_zone_page_state(page, NR_FILE_DIRTY);

			__inc_bdi_stat(mapping->backing_dev_info,

					BDI_RECLAIMABLE);

			task_dirty_inc(current);

			task_io_account_write(PAGE_CACHE_SIZE);

		}

		radix_tree_tag_set(&mapping->page_tree,

include/linux/mm.h

+1 −0
Original line number Diff line number Diff line
@@ -1159,6 +1159,7 @@ extern int filemap_fault(struct vm_area_struct *, struct vm_fault *); 


/* mm/page-writeback.c */

int write_one_page(struct page *page, int wait);

void task_dirty_inc(struct task_struct *tsk);



/* readahead.c */

#define VM_MAX_READAHEAD	128	/* kbytes */

mm/page-writeback.c

+3 −10
Original line number Diff line number Diff line
@@ -240,7 +240,7 @@ void bdi_writeout_inc(struct backing_dev_info *bdi) 
}

EXPORT_SYMBOL_GPL(bdi_writeout_inc);



static inline void task_dirty_inc(struct task_struct *tsk)

void task_dirty_inc(struct task_struct *tsk)

{

	prop_inc_single(&vm_dirties, &tsk->dirties);

}
@@ -1230,6 +1230,7 @@ int __set_page_dirty_nobuffers(struct page *page) 
				__inc_zone_page_state(page, NR_FILE_DIRTY);

				__inc_bdi_stat(mapping->backing_dev_info,

						BDI_RECLAIMABLE);

				task_dirty_inc(current);

				task_io_account_write(PAGE_CACHE_SIZE);

			}

			radix_tree_tag_set(&mapping->page_tree,
@@ -1262,7 +1263,7 @@ EXPORT_SYMBOL(redirty_page_for_writepage); 
 * If the mapping doesn't provide a set_page_dirty a_op, then

 * just fall through and assume that it wants buffer_heads.

 */

static int __set_page_dirty(struct page *page)

int set_page_dirty(struct page *page)

{

	struct address_space *mapping = page_mapping(page);
@@ -1280,14 +1281,6 @@ static int __set_page_dirty(struct page *page) 
	}

	return 0;

}



int set_page_dirty(struct page *page)

{

	int ret = __set_page_dirty(page);

	if (ret)

		task_dirty_inc(current);

	return ret;

}

EXPORT_SYMBOL(set_page_dirty);



/*

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