Commit 9bb627be authored by Li Zhong's avatar Li Zhong Committed by Linus Torvalds

mem-hotplug: don't clear the only node in new_node_page()

Commit 394e31d2 ("mem-hotplug: alloc new page from a nearest
neighbor node when mem-offline") introduced new_node_page() for memory
hotplug.

In new_node_page(), the nid is cleared before calling
__alloc_pages_nodemask().  But if it is the only node of the system, and
the first round allocation fails, it will not be able to get memory from
an empty nodemask, and will trigger oom.

The patch checks whether it is the last node on the system, and if it
is, then don't clear the nid in the nodemask.

Fixes: 394e31d2 ("mem-hotplug: alloc new page from a nearest neighbor node when mem-offline")
Link: http://lkml.kernel.org/r/1473044391.4250.19.camel@TP420Signed-off-by: default avatarLi Zhong <zhong@linux.vnet.ibm.com>
Reported-by: default avatarJohn Allen <jallen@linux.vnet.ibm.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3be79886
...@@ -1567,7 +1567,9 @@ static struct page *new_node_page(struct page *page, unsigned long private, ...@@ -1567,7 +1567,9 @@ static struct page *new_node_page(struct page *page, unsigned long private,
return alloc_huge_page_node(page_hstate(compound_head(page)), return alloc_huge_page_node(page_hstate(compound_head(page)),
next_node_in(nid, nmask)); next_node_in(nid, nmask));
if (nid != next_node_in(nid, nmask))
node_clear(nid, nmask); node_clear(nid, nmask);
if (PageHighMem(page) if (PageHighMem(page)
|| (zone_idx(page_zone(page)) == ZONE_MOVABLE)) || (zone_idx(page_zone(page)) == ZONE_MOVABLE))
gfp_mask |= __GFP_HIGHMEM; gfp_mask |= __GFP_HIGHMEM;
......
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