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authorMel Gorman <mgorman@techsingularity.net>2016-07-14 12:07:23 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-07-15 14:54:27 +0900
commitef70b6f41cda6270165a6f27b2548ed31cfa3cb2 (patch)
tree7c95bdd6a7b6426258b8791b5407736a4c423925 /mm/page_alloc.c
parente4568d3803852d00effd41dcdd489e726b998879 (diff)
downloadlwn-ef70b6f41cda6270165a6f27b2548ed31cfa3cb2.tar.gz
lwn-ef70b6f41cda6270165a6f27b2548ed31cfa3cb2.zip
mm, meminit: ensure node is online before checking whether pages are uninitialised
early_page_uninitialised looks up an arbitrary PFN. While a machine without node 0 will boot with "mm, page_alloc: Always return a valid node from early_pfn_to_nid", it works because it assumes that nodes are always in PFN order. This is not guaranteed so this patch adds robustness by always checking if the node being checked is online. Link: http://lkml.kernel.org/r/1468008031-3848-4-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: David Rientjes <rientjes@google.com> Cc: <stable@vger.kernel.org> [4.2+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page_alloc.c')
-rw-r--r--mm/page_alloc.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 5d013526bd0a..8b3e1341b754 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -286,7 +286,9 @@ static inline void reset_deferred_meminit(pg_data_t *pgdat)
/* Returns true if the struct page for the pfn is uninitialised */
static inline bool __meminit early_page_uninitialised(unsigned long pfn)
{
- if (pfn >= NODE_DATA(early_pfn_to_nid(pfn))->first_deferred_pfn)
+ int nid = early_pfn_to_nid(pfn);
+
+ if (node_online(nid) && pfn >= NODE_DATA(nid)->first_deferred_pfn)
return true;
return false;