Commit a91c43c7 authored May 19, 2016 by Joonsoo Kim Committed by Linus Torvalds May 19, 2016

mm/vmstat: add zone range overlapping check



There is a system thats node's pfns are overlapped as follows:

  -----pfn-------->
  N0 N1 N2 N0 N1 N2

Therefore, we need to care this overlapping when iterating pfn range.

There are two places in vmstat.c that iterates pfn range and they don't
consider this overlapping.  Add it.

Without this patch, above system could over count pageblock number on a
zone.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent b9eb6319

mm/vmstat.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -1010,6 +1010,9 @@ static void pagetypeinfo_showblockcount_print(struct seq_file *m,
		if (!memmap_valid_within(pfn, page, zone))
		continue;

		if (page_zone(page) != zone)
		continue;

		mtype = get_pageblock_migratetype(page);

		if (mtype < MIGRATE_TYPES)
		@@ -1076,6 +1079,10 @@ static void pagetypeinfo_showmixedcount_print(struct seq_file *m,
		continue;

		page = pfn_to_page(pfn);

		if (page_zone(page) != zone)
		continue;

		if (PageBuddy(page)) {
		pfn += (1UL << page_order(page)) - 1;
		continue;

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