+ mm-compaction-require-only-min-watermarks-for-non-costly-orders-fix.patch added to -mm tree

+ mm-compaction-require-only-min-watermarks-for-non-costly-orders-fix.patch added to -mm tree

[akpm]

The patch titled
     Subject: mm-compaction-require-only-min-watermarks-for-non-costly-orders-fix
has been added to the -mm tree.  Its filename is
     mm-compaction-require-only-min-watermarks-for-non-costly-orders-fix.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/mm-compaction-require-only-min-watermarks-for-non-costly-orders-fix.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/mm-compaction-require-only-min-watermarks-for-non-costly-orders-fix.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: Vlastimil Babka <vbabka@suse.cz>
Subject: mm-compaction-require-only-min-watermarks-for-non-costly-orders-fix
 orders-fix

Clarify why __isolate_free_page() does a order-0 watermark check with
apparent (1UL << order) gap, per Joonsoo.

Link: http://lkml.kernel.org/r/7ae4baec-4eca-e70b-2a69-94bea4fb19fa@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/page_alloc.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff -puN mm/page_alloc.c~mm-compaction-require-only-min-watermarks-for-non-costly-orders-fix mm/page_alloc.c
--- a/mm/page_alloc.c~mm-compaction-require-only-min-watermarks-for-non-costly-orders-fix
+++ a/mm/page_alloc.c
@@ -2489,7 +2489,12 @@ int __isolate_free_page(struct page *pag
 	mt = get_pageblock_migratetype(page);
 
 	if (!is_migrate_isolate(mt)) {
-		/* Obey watermarks as if the page was being allocated */
+		/*
+		 * Obey watermarks as if the page was being allocated. We can
+		 * emulate a high-order watermark check with a raised order-0
+		 * watermark, because we already know our high-order page
+		 * exists.
+		 */
 		watermark = min_wmark_pages(zone) + (1UL << order);
 		if (!zone_watermark_ok(zone, 0, watermark, 0, ALLOC_CMA))
 			return 0;
_

Patches currently in -mm which might be from vbabka@suse.cz are

mm-compaction-make-whole_zone-flag-ignore-cached-scanner-positions.patch
mm-compaction-cleanup-unused-functions.patch
mm-compaction-rename-compact_partial-to-compact_success.patch
mm-compaction-dont-recheck-watermarks-after-compact_success.patch
mm-compaction-add-the-ultimate-direct-compaction-priority.patch
mm-compaction-more-reliably-increase-direct-compaction-priority.patch
mm-compaction-use-correct-watermark-when-checking-compaction-success.patch
mm-compaction-create-compact_gap-wrapper.patch
mm-compaction-use-proper-alloc_flags-in-__compaction_suitable.patch
mm-compaction-require-only-min-watermarks-for-non-costly-orders.patch
mm-compaction-require-only-min-watermarks-for-non-costly-orders-fix.patch
mm-vmscan-make-compaction_ready-more-accurate-and-readable.patch