From 2ce13640b3f4c8721e6820476cb380fbbfaedc18 Mon Sep 17 00:00:00 2001
From: Michal Hocko <mhocko@suse.com>
Date: Thu, 6 Jul 2017 15:38:04 -0700
Subject: [PATCH] mm: __first_valid_page skip over offline pages
__first_valid_page skips over invalid pfns in the range but it might
still stumble over offline pages. At least start_isolate_page_range
will mark those set_migratetype_isolate. This doesn't represent any
immediate AFAICS because alloc_contig_range will fail to isolate those
pages but it relies on not fully initialized page which will become a
problem later when we stop associating offline pages to zones. Use
pfn_to_online_page to handle this.
This is more a preparatory patch than a fix.
Link: http://lkml.kernel.org/r/20170515085827.16474-10-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/page_isolation.c | 26 ++++++++++++++++++--------
1 file changed, 18 insertions(+), 8 deletions(-)
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index 5092e4ef00c83..3606104893e0b 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -138,12 +138,18 @@ static inline struct page *
__first_valid_page(unsigned long pfn, unsigned long nr_pages)
{
int i;
- for (i = 0; i < nr_pages; i++)
- if (pfn_valid_within(pfn + i))
- break;
- if (unlikely(i == nr_pages))
- return NULL;
- return pfn_to_page(pfn + i);
+
+ for (i = 0; i < nr_pages; i++) {
+ struct page *page;
+
+ if (!pfn_valid_within(pfn + i))
+ continue;
+ page = pfn_to_online_page(pfn + i);
+ if (!page)
+ continue;
+ return page;
+ }
+ return NULL;
}
/*
@@ -184,8 +190,12 @@ int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
undo:
for (pfn = start_pfn;
pfn < undo_pfn;
- pfn += pageblock_nr_pages)
- unset_migratetype_isolate(pfn_to_page(pfn), migratetype);
+ pfn += pageblock_nr_pages) {
+ struct page *page = pfn_to_online_page(pfn);
+ if (!page)
+ continue;
+ unset_migratetype_isolate(page, migratetype);
+ }
return -EBUSY;
}
--
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