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| author |   Peter Zijlstra <peterz@infradead.org> | 2007-11-14 16:59:15 -0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-11-14 18:45:38 -0800 |
| commit | 5fce25a9df4865bdd5e3dc4853b269dc1677a02a (patch) | |
| tree | 207fe2bf726bac89e402eb738b9548cfc7cae2f5 /mm | |
| parent | make getdelays cgroupstats aware (diff) | |
| download | linux-dev-5fce25a9df4865bdd5e3dc4853b269dc1677a02a.tar.xz linux-dev-5fce25a9df4865bdd5e3dc4853b269dc1677a02a.zip | |
mm: speed up writeback ramp-up on clean systems
We allow violation of bdi limits if there is a lot of room on the system.
Once we hit half the total limit we start enforcing bdi limits and bdi
ramp-up should happen. Doing it this way avoids many small writeouts on an
otherwise idle system and should also speed up the ramp-up.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/page-writeback.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 838a5e31394c..81a91e6f1f99 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -355,8 +355,8 @@ get_dirty_limits(long *pbackground, long *pdirty, long *pbdi_dirty, */ static void balance_dirty_pages(struct address_space *mapping) { - long bdi_nr_reclaimable; - long bdi_nr_writeback; + long nr_reclaimable, bdi_nr_reclaimable; + long nr_writeback, bdi_nr_writeback; long background_thresh; long dirty_thresh; long bdi_thresh; @@ -376,11 +376,26 @@ static void balance_dirty_pages(struct address_space *mapping) get_dirty_limits(&background_thresh, &dirty_thresh, &bdi_thresh, bdi); + + nr_reclaimable = global_page_state(NR_FILE_DIRTY) + + global_page_state(NR_UNSTABLE_NFS); + nr_writeback = global_page_state(NR_WRITEBACK); + bdi_nr_reclaimable = bdi_stat(bdi, BDI_RECLAIMABLE); bdi_nr_writeback = bdi_stat(bdi, BDI_WRITEBACK); + if (bdi_nr_reclaimable + bdi_nr_writeback <= bdi_thresh) break; + /* + * Throttle it only when the background writeback cannot + * catch-up. This avoids (excessively) small writeouts + * when the bdi limits are ramping up. + */ + if (nr_reclaimable + nr_writeback < + (background_thresh + dirty_thresh) / 2) + break; + if (!bdi->dirty_exceeded) bdi->dirty_exceeded = 1; |