The patch titled
Subject: mm/vmscan: delay waking of tasks throttled on NOPROGRESS
has been added to the -mm tree. Its filename is
mm-vmscan-delay-waking-of-tasks-throttled-on-noprogress.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-vmscan-delay-waking-of-tasks-throttled-on-noprogress.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-vmscan-delay-waking-of-tasks-throttled-on-noprogress.patch
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------------------------------------------------------
From: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Subject: mm/vmscan: delay waking of tasks throttled on NOPROGRESS
Tracing indicates that tasks throttled on NOPROGRESS are woken prematurely
resulting in occasional massive spikes in direct reclaim activity. This
patch wakes tasks throttled on NOPROGRESS if reclaim efficiency is at
least 12%.
Link: https://lkml.kernel.org/r/20211022144651.19914-9-mgorman@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Andreas Dilger <adilger.kernel@xxxxxxxxx>
Cc: "Darrick J . Wong" <djwong@xxxxxxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: NeilBrown <neilb@xxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxxx>
Cc: "Theodore Ts'o" <tytso@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmscan.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
--- a/mm/vmscan.c~mm-vmscan-delay-waking-of-tasks-throttled-on-noprogress
+++ a/mm/vmscan.c
@@ -3355,8 +3355,11 @@ static inline bool compaction_ready(stru
static void consider_reclaim_throttle(pg_data_t *pgdat, struct scan_control *sc)
{
- /* If reclaim is making progress, wake any throttled tasks. */
- if (sc->nr_reclaimed) {
+ /*
+ * If reclaim is making progress greater than 12% efficiency then
+ * wake all the NOPROGRESS throttled tasks.
+ */
+ if (sc->nr_reclaimed > (sc->nr_scanned >> 3)) {
wait_queue_head_t *wqh;
wqh = &pgdat->reclaim_wait[VMSCAN_THROTTLE_NOPROGRESS];
_
Patches currently in -mm which might be from mgorman@xxxxxxxxxxxxxxxxxxx are
mm-vmscan-throttle-reclaim-until-some-writeback-completes-if-congested.patch
mm-vmscan-throttle-reclaim-and-compaction-when-too-may-pages-are-isolated.patch
mm-vmscan-throttle-reclaim-when-no-progress-is-being-made.patch
mm-writeback-throttle-based-on-page-writeback-instead-of-congestion.patch
mm-page_alloc-remove-the-throttling-logic-from-the-page-allocator.patch
mm-vmscan-centralise-timeout-values-for-reclaim_throttle.patch
mm-vmscan-increase-the-timeout-if-page-reclaim-is-not-making-progress.patch
mm-vmscan-delay-waking-of-tasks-throttled-on-noprogress.patch
