From: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Subject: 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@xxxxxxxxxxxxxxxxxxx remove redundant check in shrink_zones()] Link: http://lkml.kernel.org/r/1468588165-12461-3-git-send-email-mgorman@xxxxxxxxxxxxxxxxxxx Link: http://lkml.kernel.org/r/1467970510-21195-26-git-send-email-mgorman@xxxxxxxxxxxxxxxxxxx Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Acked-by: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/vmscan.c | 27 +++++++-------------------- 1 file changed, 7 insertions(+), 20 deletions(-) diff -puN mm/vmscan.c~mm-vmscan-avoid-passing-in-classzone_idx-unnecessarily-to-compaction_ready mm/vmscan.c --- a/mm/vmscan.c~mm-vmscan-avoid-passing-in-classzone_idx-unnecessarily-to-compaction_ready +++ a/mm/vmscan.c @@ -2523,7 +2523,7 @@ static bool shrink_node(pg_data_t *pgdat * 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 @@ static inline bool compaction_ready(stru * 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 @@ static void shrink_zones(struct zonelist 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 @@ static void shrink_zones(struct zonelist 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 @@ static void shrink_zones(struct zonelist 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 @@ static void shrink_zones(struct zonelist */ 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; } _ -- 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
