The patch titled
Subject: vmscan: abort reclaim/compaction if compaction can proceed
has been added to the -mm tree. Its filename is
vmscan-abort-reclaim-compaction-if-compaction-can-proceed.patch
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------------------------------------------------------
From: Mel Gorman <mgorman@xxxxxxx>
Subject: vmscan: abort reclaim/compaction if compaction can proceed
If compaction can proceed, shrink_zones() stops doing any work but its
callers still call shrink_slab() which raises the priority and potentially
sleeps. This is unnecessary and wasteful so this patch aborts direct
reclaim/compaction entirely if compaction can proceed.
Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
Acked-by: Rik van Riel <riel@xxxxxxxxxx>
Reviewed-by: Minchan Kim <minchan.kim@xxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Josh Boyer <jwboyer@xxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxx>
---
mm/vmscan.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
diff -puN mm/vmscan.c~vmscan-abort-reclaim-compaction-if-compaction-can-proceed mm/vmscan.c
--- a/mm/vmscan.c~vmscan-abort-reclaim-compaction-if-compaction-can-proceed
+++ a/mm/vmscan.c
@@ -2091,14 +2091,19 @@ restart:
*
* If a zone is deemed to be full of pinned pages then just give it a light
* scan then give up on it.
+ *
+ * This function returns true if a zone is being reclaimed for a costly
+ * high-order allocation and compaction is either ready to begin or deferred.
+ * This indicates to the caller that it should retry the allocation or fail.
*/
-static void shrink_zones(int priority, struct zonelist *zonelist,
+static bool shrink_zones(int priority, struct zonelist *zonelist,
struct scan_control *sc)
{
struct zoneref *z;
struct zone *zone;
unsigned long nr_soft_reclaimed;
unsigned long nr_soft_scanned;
+ bool should_abort_reclaim = false;
for_each_zone_zonelist_nodemask(zone, z, zonelist,
gfp_zone(sc->gfp_mask), sc->nodemask) {
@@ -2116,12 +2121,15 @@ static void shrink_zones(int priority, s
if (COMPACTION_BUILD) {
/*
* If we already have plenty of memory free
- * for compaction, don't free any more.
+ * for compaction in this zone , don't free any
+ * more.
*/
if (sc->order > PAGE_ALLOC_COSTLY_ORDER &&
(compaction_suitable(zone, sc->order) ||
- compaction_deferred(zone)))
+ compaction_deferred(zone))) {
+ should_abort_reclaim = true;
continue;
+ }
}
/*
* This steals pages from memory cgroups over softlimit
@@ -2140,6 +2148,8 @@ static void shrink_zones(int priority, s
shrink_zone(priority, zone, sc);
}
+
+ return should_abort_reclaim;
}
static bool zone_reclaimable(struct zone *zone)
@@ -2204,7 +2214,9 @@ static unsigned long do_try_to_free_page
sc->nr_scanned = 0;
if (!priority)
disable_swap_token(sc->mem_cgroup);
- shrink_zones(priority, zonelist, sc);
+ if (shrink_zones(priority, zonelist, sc))
+ break;
+
/*
* Don't shrink slabs when reclaiming memory from
* over limit cgroups
_
Subject: Subject: vmscan: abort reclaim/compaction if compaction can proceed
Patches currently in -mm which might be from mgorman@xxxxxxx are
mm-compaction-trivial-clean-up-in-acct_isolated.patch
mm-change-isolate-mode-from-define-to-bitwise-type.patch
mm-change-isolate-mode-from-define-to-bitwise-type-fix.patch
mm-compaction-make-isolate_lru_page-filter-aware.patch
mm-compaction-make-isolate_lru_page-filter-aware-fix.patch
mm-zone_reclaim-make-isolate_lru_page-filter-aware.patch
mm-zone_reclaim-make-isolate_lru_page-filter-aware-fix.patch
mm-migration-clean-up-unmap_and_move.patch
mm-page-writebackc-make-determine_dirtyable_memory-static-again.patch
mm-vmscan-do-not-writeback-filesystem-pages-in-direct-reclaim.patch
mm-vmscan-remove-dead-code-related-to-lumpy-reclaim-waiting-on-pages-under-writeback.patch
xfs-warn-if-direct-reclaim-tries-to-writeback-pages.patch
ext4-warn-if-direct-reclaim-tries-to-writeback-pages.patch
mm-vmscan-do-not-writeback-filesystem-pages-in-kswapd-except-in-high-priority.patch
mm-vmscan-throttle-reclaim-if-encountering-too-many-dirty-pages-under-writeback.patch
mm-vmscan-throttle-reclaim-if-encountering-too-many-dirty-pages-under-writeback-update.patch
mm-vmscan-immediately-reclaim-end-of-lru-dirty-pages-when-writeback-completes.patch
vmscan-count-pages-into-balanced-for-zone-with-good-watermark.patch
mremap-check-for-overflow-using-deltas.patch
mremap-avoid-sending-one-ipi-per-page.patch
thp-mremap-support-and-tlb-optimization.patch
thp-mremap-support-and-tlb-optimization-fix.patch
thp-mremap-support-and-tlb-optimization-fix-fix.patch
kswapd-avoid-unnecessary-rebalance-after-an-unsuccessful-balancing.patch
kswapd-assign-new_order-and-new_classzone_idx-after-wakeup-in-sleeping.patch
vmscan-limit-direct-reclaim-for-higher-order-allocations.patch
vmscan-abort-reclaim-compaction-if-compaction-can-proceed.patch
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