The patch titled
Subject: vmscan: abort reclaim/compaction if compaction can proceed
has been removed from the -mm tree. Its filename was
vmscan-abort-reclaim-compaction-if-compaction-can-proceed.patch
This patch was dropped because it was merged into mainline or a subsystem tree
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
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>
Acked-by: Johannes Weiner <jweiner@xxxxxxxxxx>
Cc: Josh Boyer <jwboyer@xxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmscan.c | 32 +++++++++++++++++++++-----------
1 file changed, 21 insertions(+), 11 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
@@ -2103,14 +2103,19 @@ 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) {
@@ -2127,19 +2132,20 @@ static void shrink_zones(int priority, s
continue; /* Let kswapd poll it */
if (COMPACTION_BUILD) {
/*
- * If we already have plenty of memory
- * free for compaction, don't free any
- * more. Even though compaction is
- * invoked for any non-zero order,
- * only frequent costly order
- * reclamation is disruptive enough to
- * become a noticable problem, like
- * transparent huge page allocations.
+ * If we already have plenty of memory free for
+ * compaction in this zone, don't free any more.
+ * Even though compaction is invoked for any
+ * non-zero order, only frequent costly order
+ * reclamation is disruptive enough to become a
+ * noticable problem, like transparent huge page
+ * allocations.
*/
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
@@ -2158,6 +2164,8 @@ static void shrink_zones(int priority, s
shrink_zone(priority, zone, sc);
}
+
+ return should_abort_reclaim;
}
static bool zone_reclaimable(struct zone *zone)
@@ -2222,7 +2230,9 @@ 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
_
Patches currently in -mm which might be from mgorman@xxxxxxx are
origin.patch
mm-page-writebackc-make-determine_dirtyable_memory-static-again.patch
thp-tail-page-refcounting-fix-5.patch
powerpc-remove-superfluous-pagetail-checks-on-the-pte-gup_fast.patch
powerpc-get_hugepte-dont-put_page-the-wrong-page.patch
powerpc-gup_hugepte-avoid-to-free-the-head-page-too-many-times.patch
powerpc-gup_hugepte-support-thp-based-tail-recounting.patch
powerpc-gup_huge_pmd-return-0-if-pte-changes.patch
s390-gup_huge_pmd-support-thp-tail-recounting.patch
s390-gup_huge_pmd-return-0-if-pte-changes.patch
sparc-gup_pte_range-support-thp-based-tail-recounting.patch
thp-share-get_huge_page_tail.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
