The patch titled Subject: mm, vmscan: have kswapd only scan based on the highest requested zone has been added to the -mm tree. Its filename is mm-vmscan-have-kswapd-only-scan-based-on-the-highest-requested-zone.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-vmscan-have-kswapd-only-scan-based-on-the-highest-requested-zone.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-vmscan-have-kswapd-only-scan-based-on-the-highest-requested-zone.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Subject: mm, vmscan: have kswapd only scan based on the highest requested zone kswapd checks all eligible zones to see if they need balancing even if it was woken for a lower zone. This made sense when we reclaimed on a per-zone basis because we wanted to shrink zones fairly so avoid age-inversion problems. Ideally this is completely unnecessary when reclaiming on a per-node basis. In theory, there may still be anomalies when all requests are for lower zones and very old pages are preserved in higher zones but this should be the exceptional case. Link: http://lkml.kernel.org/r/1466518566-30034-6-git-send-email-mgorman@xxxxxxxxxxxxxxxxxxx Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/vmscan.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff -puN mm/vmscan.c~mm-vmscan-have-kswapd-only-scan-based-on-the-highest-requested-zone mm/vmscan.c --- a/mm/vmscan.c~mm-vmscan-have-kswapd-only-scan-based-on-the-highest-requested-zone +++ a/mm/vmscan.c @@ -3207,11 +3207,8 @@ static int balance_pgdat(pg_data_t *pgda sc.nr_reclaimed = 0; - /* - * Scan in the highmem->dma direction for the highest - * zone which needs scanning - */ - for (i = pgdat->nr_zones - 1; i >= 0; i--) { + /* Scan from the highest requested zone to dma */ + for (i = classzone_idx; i >= 0; i--) { struct zone *zone = pgdat->node_zones + i; if (!populated_zone(zone)) _ Patches currently in -mm which might be from mgorman@xxxxxxxxxxxxxxxxxxx are mm-slaub-add-__gfp_atomic-to-the-gfp-reclaim-mask.patch mm-vmstat-add-infrastructure-for-per-node-vmstats.patch mm-vmscan-move-lru_lock-to-the-node.patch mm-vmscan-move-lru-lists-to-node.patch mm-vmscan-begin-reclaiming-pages-on-a-per-node-basis.patch mm-vmscan-have-kswapd-only-scan-based-on-the-highest-requested-zone.patch mm-vmscan-make-kswapd-reclaim-in-terms-of-nodes.patch mm-vmscan-remove-balance-gap.patch mm-vmscan-simplify-the-logic-deciding-whether-kswapd-sleeps.patch mm-vmscan-by-default-have-direct-reclaim-only-shrink-once-per-node.patch mm-vmscan-remove-duplicate-logic-clearing-node-congestion-and-dirty-state.patch mm-vmscan-do-not-reclaim-from-kswapd-if-there-is-any-eligible-zone.patch mm-vmscan-make-shrink_node-decisions-more-node-centric.patch mm-memcg-move-memcg-limit-enforcement-from-zones-to-nodes.patch mm-workingset-make-working-set-detection-node-aware.patch mm-page_alloc-consider-dirtyable-memory-in-terms-of-nodes.patch mm-move-page-mapped-accounting-to-the-node.patch mm-rename-nr_anon_pages-to-nr_anon_mapped.patch mm-move-most-file-based-accounting-to-the-node.patch mm-move-vmscan-writes-and-file-write-accounting-to-the-node.patch mm-vmscan-update-classzone_idx-if-buffer_heads_over_limit.patch mm-vmscan-only-wakeup-kswapd-once-per-node-for-the-requested-classzone.patch mm-convert-zone_reclaim-to-node_reclaim.patch mm-vmscan-add-classzone-information-to-tracepoints.patch mm-page_alloc-remove-fair-zone-allocation-policy.patch mm-page_alloc-cache-the-last-node-whose-dirty-limit-is-reached.patch mm-vmstat-replace-__count_zone_vm_events-with-a-zone-id-equivalent.patch mm-vmstat-account-per-zone-stalls-and-pages-skipped-during-reclaim.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