From ccbe1e4ddece5ef9d83f2af7f28733efe6ae806a Mon Sep 17 00:00:00 2001
From: Michal Hocko <mhocko@suse.com>
Date: Thu, 6 Jul 2017 15:38:00 -0700
Subject: [PATCH] mm, compaction: skip over holes in __reset_isolation_suitable

__reset_isolation_suitable walks the whole zone pfn range and it tries
to jump over holes by checking the zone for each page.  It might still
stumble over offline pages, though.  Skip those by checking
pfn_to_online_page()

Link: http://lkml.kernel.org/r/20170515085827.16474-9-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Daniel Kiper <daniel.kiper@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Tobias Regnery <tobias.regnery@gmail.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 mm/compaction.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/mm/compaction.c b/mm/compaction.c
index 613c59e928cb..fb548e4c7bd4 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -236,10 +236,9 @@ static void __reset_isolation_suitable(struct zone *zone)
 
 		cond_resched();
 
-		if (!pfn_valid(pfn))
+		page = pfn_to_online_page(pfn);
+		if (!page)
 			continue;
-
-		page = pfn_to_page(pfn);
 		if (zone != page_zone(page))
 			continue;
 
-- 
2.20.1