The patch titled
mm: speed up writeback ramp-up on clean systems
has been added to the -mm tree. Its filename is
mm-speed-up-writeback-ramp-up-on-clean-systems.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: mm: speed up writeback ramp-up on clean systems
From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
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@xxxxxxxxx>
Reviewed-by: Fengguang Wu <wfg@xxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page-writeback.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)
diff -puN mm/page-writeback.c~mm-speed-up-writeback-ramp-up-on-clean-systems mm/page-writeback.c
--- a/mm/page-writeback.c~mm-speed-up-writeback-ramp-up-on-clean-systems
+++ a/mm/page-writeback.c
@@ -355,8 +355,8 @@ get_dirty_limits(long *pbackground, long
*/
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 a
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;
_
Patches currently in -mm which might be from peterz@xxxxxxxxxxxxx are
mm-speed-up-writeback-ramp-up-on-clean-systems.patch
reiserfs-dont-drop-pg_dirty-when-releasing-sub-page-sized-dirty-file.patch
-
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