Subject: [merged] mm-vmscan-decide-whether-to-compact-the-pgdat-based-on-reclaim-progress.patch removed from -mm tree
To: mgorman@xxxxxxx,Valdis.Kletnieks@xxxxxx,dormando@xxxxxxxxx,hannes@xxxxxxxxxxx,jslaby@xxxxxxx,kamezawa.hiroyu@xxxxxxxxxxxxxx,mhocko@xxxxxxx,riel@xxxxxxxxxx,zcalusic@xxxxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Mon, 08 Jul 2013 12:24:39 -0700
The patch titled
Subject: mm: vmscan: decide whether to compact the pgdat based on reclaim progress
has been removed from the -mm tree. Its filename was
mm-vmscan-decide-whether-to-compact-the-pgdat-based-on-reclaim-progress.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Mel Gorman <mgorman@xxxxxxx>
Subject: mm: vmscan: decide whether to compact the pgdat based on reclaim progress
In the past, kswapd makes a decision on whether to compact memory after
the pgdat was considered balanced. This more or less worked but it is
late to make such a decision and does not fit well now that kswapd makes a
decision whether to exit the zone scanning loop depending on reclaim
progress.
This patch will compact a pgdat if at least the requested number of pages
were reclaimed from unbalanced zones for a given priority. If any zone is
currently balanced, kswapd will not call compaction as it is expected the
necessary pages are already available.
Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Reviewed-by: Michal Hocko <mhocko@xxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Jiri Slaby <jslaby@xxxxxxx>
Cc: Valdis Kletnieks <Valdis.Kletnieks@xxxxxx>
Tested-by: Zlatko Calusic <zcalusic@xxxxxxxxxxx>
Cc: dormando <dormando@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmscan.c | 59 +++++++++++++++++++++++++-------------------------
1 file changed, 30 insertions(+), 29 deletions(-)
diff -puN mm/vmscan.c~mm-vmscan-decide-whether-to-compact-the-pgdat-based-on-reclaim-progress mm/vmscan.c
--- a/mm/vmscan.c~mm-vmscan-decide-whether-to-compact-the-pgdat-based-on-reclaim-progress
+++ a/mm/vmscan.c
@@ -2661,7 +2661,8 @@ static bool prepare_kswapd_sleep(pg_data
*/
static bool kswapd_shrink_zone(struct zone *zone,
struct scan_control *sc,
- unsigned long lru_pages)
+ unsigned long lru_pages,
+ unsigned long *nr_attempted)
{
unsigned long nr_slab;
struct reclaim_state *reclaim_state = current->reclaim_state;
@@ -2677,6 +2678,9 @@ static bool kswapd_shrink_zone(struct zo
nr_slab = shrink_slab(&shrink, sc->nr_scanned, lru_pages);
sc->nr_reclaimed += reclaim_state->reclaimed_slab;
+ /* Account for the number of pages attempted to reclaim */
+ *nr_attempted += sc->nr_to_reclaim;
+
if (nr_slab == 0 && !zone_reclaimable(zone))
zone->all_unreclaimable = 1;
@@ -2724,7 +2728,9 @@ static unsigned long balance_pgdat(pg_da
do {
unsigned long lru_pages = 0;
+ unsigned long nr_attempted = 0;
bool raise_priority = true;
+ bool pgdat_needs_compaction = (order > 0);
sc.nr_reclaimed = 0;
@@ -2774,7 +2780,21 @@ static unsigned long balance_pgdat(pg_da
for (i = 0; i <= end_zone; i++) {
struct zone *zone = pgdat->node_zones + i;
+ if (!populated_zone(zone))
+ continue;
+
lru_pages += zone_reclaimable_pages(zone);
+
+ /*
+ * If any zone is currently balanced then kswapd will
+ * not call compaction as it is expected that the
+ * necessary pages are already available.
+ */
+ if (pgdat_needs_compaction &&
+ zone_watermark_ok(zone, order,
+ low_wmark_pages(zone),
+ *classzone_idx, 0))
+ pgdat_needs_compaction = false;
}
/*
@@ -2843,7 +2863,8 @@ static unsigned long balance_pgdat(pg_da
* already being scanned that high
* watermark would be met at 100% efficiency.
*/
- if (kswapd_shrink_zone(zone, &sc, lru_pages))
+ if (kswapd_shrink_zone(zone, &sc, lru_pages,
+ &nr_attempted))
raise_priority = false;
}
@@ -2896,6 +2917,13 @@ static unsigned long balance_pgdat(pg_da
break;
/*
+ * Compact if necessary and kswapd is reclaiming at least the
+ * high watermark number of pages as requsted
+ */
+ if (pgdat_needs_compaction && sc.nr_reclaimed > nr_attempted)
+ compact_pgdat(pgdat, order);
+
+ /*
* Raise priority if scanning rate is too low or there was no
* progress in reclaiming pages
*/
@@ -2904,33 +2932,6 @@ static unsigned long balance_pgdat(pg_da
} while (sc.priority >= 0 &&
!pgdat_balanced(pgdat, order, *classzone_idx));
- /*
- * If kswapd was reclaiming at a higher order, it has the option of
- * sleeping without all zones being balanced. Before it does, it must
- * ensure that the watermarks for order-0 on *all* zones are met and
- * that the congestion flags are cleared. The congestion flag must
- * be cleared as kswapd is the only mechanism that clears the flag
- * and it is potentially going to sleep here.
- */
- if (order) {
- int zones_need_compaction = 1;
-
- for (i = 0; i <= end_zone; i++) {
- struct zone *zone = pgdat->node_zones + i;
-
- if (!populated_zone(zone))
- continue;
-
- /* Check if the memory needs to be defragmented. */
- if (zone_watermark_ok(zone, order,
- low_wmark_pages(zone), *classzone_idx, 0))
- zones_need_compaction = 0;
- }
-
- if (zones_need_compaction)
- compact_pgdat(pgdat, order);
- }
-
out:
/*
* Return the order we were reclaiming at so prepare_kswapd_sleep()
_
Patches currently in -mm which might be from mgorman@xxxxxxx are
origin.patch
linux-next.patch
fs-bump-inode-and-dentry-counters-to-long.patch
super-fix-calculation-of-shrinkable-objects-for-small-numbers.patch
dcache-convert-dentry_statnr_unused-to-per-cpu-counters.patch
dentry-move-to-per-sb-lru-locks.patch
dcache-remove-dentries-from-lru-before-putting-on-dispose-list.patch
mm-new-shrinker-api.patch
shrinker-convert-superblock-shrinkers-to-new-api.patch
list-add-a-new-lru-list-type.patch
inode-convert-inode-lru-list-to-generic-lru-list-code.patch
dcache-convert-to-use-new-lru-list-infrastructure.patch
list_lru-per-node-list-infrastructure.patch
list_lru-per-node-api.patch
shrinker-add-node-awareness.patch
vmscan-per-node-deferred-work.patch
fs-convert-inode-and-dentry-shrinking-to-be-node-aware.patch
xfs-convert-buftarg-lru-to-generic-code.patch
xfs-rework-buffer-dispose-list-tracking.patch
xfs-convert-dquot-cache-lru-to-list_lru.patch
fs-convert-fs-shrinkers-to-new-scan-count-api.patch
drivers-convert-shrinkers-to-new-count-scan-api.patch
i915-bail-out-earlier-when-shrinker-cannot-acquire-mutex.patch
shrinker-convert-remaining-shrinkers-to-count-scan-api.patch
hugepage-convert-huge-zero-page-shrinker-to-new-shrinker-api.patch
shrinker-kill-old-shrink-api.patch
list_lru-dynamically-adjust-node-arrays.patch
zbud-add-to-mm.patch
zswap-add-to-mm.patch
zswap-add-documentation.patch
mm-vmscan-do-not-continue-scanning-if-reclaim-was-aborted-for-compaction.patch
mm-vmscan-do-not-scale-writeback-pages-when-deciding-whether-to-set-zone_writeback.patch
mm-memmap_init_zone-performance-improvement.patch
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