mm, vmscan: avoid passing in classzone_idx unnecessarily to compaction_ready
The scan_control structure has enough information available for
compaction_ready() to make a decision. The classzone_idx manipulations
in shrink_zones() are no longer necessary as the highest populated zone
is no longer used to determine if shrink_slab should be called or not.
[mgorman@techsingularity.net remove redundant check in shrink_zones()]
Link: http://lkml.kernel.org/r/1468588165-12461-3-git-send-email-mgorman@techsingularity.net
Link: http://lkml.kernel.org/r/1467970510-21195-26-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 7bfc0fe..a9bd8b2 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2523,7 +2523,7 @@
* Returns true if compaction should go ahead for a high-order request, or
* the high-order allocation would succeed without compaction.
*/
-static inline bool compaction_ready(struct zone *zone, int order, int classzone_idx)
+static inline bool compaction_ready(struct zone *zone, struct scan_control *sc)
{
unsigned long watermark;
bool watermark_ok;
@@ -2534,21 +2534,21 @@
* there is a buffer of free pages available to give compaction
* a reasonable chance of completing and allocating the page
*/
- watermark = high_wmark_pages(zone) + (2UL << order);
- watermark_ok = zone_watermark_ok_safe(zone, 0, watermark, classzone_idx);
+ watermark = high_wmark_pages(zone) + (2UL << sc->order);
+ watermark_ok = zone_watermark_ok_safe(zone, 0, watermark, sc->reclaim_idx);
/*
* If compaction is deferred, reclaim up to a point where
* compaction will have a chance of success when re-enabled
*/
- if (compaction_deferred(zone, order))
+ if (compaction_deferred(zone, sc->order))
return watermark_ok;
/*
* If compaction is not ready to start and allocation is not likely
* to succeed without it, then keep reclaiming.
*/
- if (compaction_suitable(zone, order, 0, classzone_idx) == COMPACT_SKIPPED)
+ if (compaction_suitable(zone, sc->order, 0, sc->reclaim_idx) == COMPACT_SKIPPED)
return false;
return watermark_ok;
@@ -2569,7 +2569,6 @@
unsigned long nr_soft_reclaimed;
unsigned long nr_soft_scanned;
gfp_t orig_mask;
- enum zone_type classzone_idx;
pg_data_t *last_pgdat = NULL;
/*
@@ -2580,7 +2579,7 @@
orig_mask = sc->gfp_mask;
if (buffer_heads_over_limit) {
sc->gfp_mask |= __GFP_HIGHMEM;
- sc->reclaim_idx = classzone_idx = gfp_zone(sc->gfp_mask);
+ sc->reclaim_idx = gfp_zone(sc->gfp_mask);
}
for_each_zone_zonelist_nodemask(zone, z, zonelist,
@@ -2589,17 +2588,6 @@
continue;
/*
- * Note that reclaim_idx does not change as it is the highest
- * zone reclaimed from which for empty zones is a no-op but
- * classzone_idx is used by shrink_node to test if the slabs
- * should be shrunk on a given node.
- */
- classzone_idx = sc->reclaim_idx;
- while (!populated_zone(zone->zone_pgdat->node_zones +
- classzone_idx))
- classzone_idx--;
-
- /*
* Take care memory controller reclaiming has small influence
* to global LRU.
*/
@@ -2623,8 +2611,7 @@
*/
if (IS_ENABLED(CONFIG_COMPACTION) &&
sc->order > PAGE_ALLOC_COSTLY_ORDER &&
- zonelist_zone_idx(z) <= classzone_idx &&
- compaction_ready(zone, sc->order, classzone_idx)) {
+ compaction_ready(zone, sc)) {
sc->compaction_ready = true;
continue;
}