+ mm-vmscan-kick-flushers-when-we-encounter-dirty-pages-on-the-lru-fix.patch added to -mm tree

+ mm-vmscan-kick-flushers-when-we-encounter-dirty-pages-on-the-lru-fix.patch added to -mm tree

[akpm]

The patch titled
     Subject: mm: vmscan: kick flushers when we encounter dirty pages on the LRU fix
has been added to the -mm tree.  Its filename is
     mm-vmscan-kick-flushers-when-we-encounter-dirty-pages-on-the-lru-fix.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/mm-vmscan-kick-flushers-when-we-encounter-dirty-pages-on-the-lru-fix.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/mm-vmscan-kick-flushers-when-we-encounter-dirty-pages-on-the-lru-fix.patch

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------------------------------------------------------
From: Johannes Weiner <hannes@cmpxchg.org>
Subject: mm: vmscan: kick flushers when we encounter dirty pages on the LRU fix

Mention dirty expiration as a condition: we need dirty data that is too
recent for periodic flushing and not large enough for waking up limit
flushing.  As per Mel.

Link: http://lkml.kernel.org/r/20170126174739.GA30636@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/vmscan.c |   16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff -puN mm/vmscan.c~mm-vmscan-kick-flushers-when-we-encounter-dirty-pages-on-the-lru-fix mm/vmscan.c
--- a/mm/vmscan.c~mm-vmscan-kick-flushers-when-we-encounter-dirty-pages-on-the-lru-fix
+++ a/mm/vmscan.c
@@ -1799,14 +1799,14 @@ shrink_inactive_list(unsigned long nr_to
 		/*
 		 * If dirty pages are scanned that are not queued for IO, it
 		 * implies that flushers are not doing their job. This can
-		 * happen when memory pressure pushes dirty pages to the end
-		 * of the LRU without the dirty limits being breached. It can
-		 * also happen when the proportion of dirty pages grows not
-		 * through writes but through memory pressure reclaiming all
-		 * the clean cache. And in some cases, the flushers simply
-		 * cannot keep up with the allocation rate. Nudge the flusher
-		 * threads in case they are asleep, but also allow kswapd to
-		 * start writing pages during reclaim.
+		 * happen when memory pressure pushes dirty pages to the end of
+		 * the LRU before the dirty limits are breached and the dirty
+		 * data has expired. It can also happen when the proportion of
+		 * dirty pages grows not through writes but through memory
+		 * pressure reclaiming all the clean cache. And in some cases,
+		 * the flushers simply cannot keep up with the allocation
+		 * rate. Nudge the flusher threads in case they are asleep, but
+		 * also allow kswapd to start writing pages during reclaim.
 		 */
 		if (stat.nr_unqueued_dirty == nr_taken) {
 			wakeup_flusher_threads(0, WB_REASON_VMSCAN);
_

Patches currently in -mm which might be from hannes@cmpxchg.org are

mm-vmscan-scan-dirty-pages-even-in-laptop-mode.patch
mm-vmscan-kick-flushers-when-we-encounter-dirty-pages-on-the-lru.patch
mm-vmscan-kick-flushers-when-we-encounter-dirty-pages-on-the-lru-fix.patch
mm-vmscan-remove-old-flusher-wakeup-from-direct-reclaim-path.patch
mm-vmscan-only-write-dirty-pages-that-the-scanner-has-seen-twice.patch
mm-vmscan-move-dirty-pages-out-of-the-way-until-theyre-flushed.patch