diff options
author | Wu Fengguang <fengguang.wu@intel.com> | 2011-08-08 17:22:00 -0400 |
---|---|---|
committer | Wu Fengguang <fengguang.wu@intel.com> | 2011-12-18 01:20:23 -0500 |
commit | 2f800fbd777b792de54187088df19a7df0251254 (patch) | |
tree | 2dc813b41da42d647468dafcf49a0b9e673df8b5 /include | |
parent | d3bc1fef9389e409a772ea174a5e41a6f93d9b7b (diff) |
writeback: fix dirtied pages accounting on redirty
De-account the accumulative dirty counters on page redirty.
Page redirties (very common in ext4) will introduce mismatch between
counters (a) and (b)
a) NR_DIRTIED, BDI_DIRTIED, tsk->nr_dirtied
b) NR_WRITTEN, BDI_WRITTEN
This will introduce systematic errors in balanced_rate and result in
dirty page position errors (ie. the dirty pages are no longer balanced
around the global/bdi setpoints).
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/writeback.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 05eaf5e3aad7..b30419cd425e 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h | |||
@@ -197,6 +197,8 @@ void writeback_set_ratelimit(void); | |||
197 | void tag_pages_for_writeback(struct address_space *mapping, | 197 | void tag_pages_for_writeback(struct address_space *mapping, |
198 | pgoff_t start, pgoff_t end); | 198 | pgoff_t start, pgoff_t end); |
199 | 199 | ||
200 | void account_page_redirty(struct page *page); | ||
201 | |||
200 | /* pdflush.c */ | 202 | /* pdflush.c */ |
201 | extern int nr_pdflush_threads; /* Global so it can be exported to sysctl | 203 | extern int nr_pdflush_threads; /* Global so it can be exported to sysctl |
202 | read-only. */ | 204 | read-only. */ |