Commit 231e97e2 authored Sep 28, 2016 by Li Zhong Committed by Linus Torvalds Sep 28, 2016

mem-hotplug: use nodes that contain memory as mask in new_node_page()

9bb627be ("mem-hotplug: don't clear the only node in new_node_page()")
prevents allocating from an empty nodemask, but as David points out, it is
still wrong.  As node_online_map may include memoryless nodes, only
allocating from these nodes is meaningless.

This patch uses node_states[N_MEMORY] mask to prevent the above case.

Fixes: 9bb627be ("mem-hotplug: don't clear the only node in new_node_page()")
Fixes: 394e31d2 ("mem-hotplug: alloc new page from a nearest neighbor node when mem-offline")
Link: http://lkml.kernel.org/r/1474447117.28370.6.camel@TP420


Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Suggested-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: John Allen <jallen@linux.vnet.ibm.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent e436fd61

mm/memory_hotplug.c

+5 −5

Original line number	Diff line number	Diff line
		@@ -1555,8 +1555,8 @@ static struct page new_node_page(struct page page, unsigned long private,
		{
		gfp_t gfp_mask = GFP_USER \| __GFP_MOVABLE;
		int nid = page_to_nid(page);
		nodemask_t nmask = node_online_map;
		struct page *new_page;
		nodemask_t nmask = node_states[N_MEMORY];
		struct page *new_page = NULL;

		/*
		* TODO: allocate a destination hugepage from a nearest neighbor node,
		@@ -1567,13 +1567,13 @@ static struct page new_node_page(struct page page, unsigned long private,
		return alloc_huge_page_node(page_hstate(compound_head(page)),
		next_node_in(nid, nmask));

		if (nid != next_node_in(nid, nmask))
		node_clear(nid, nmask);

		if (PageHighMem(page)
		\|\| (zone_idx(page_zone(page)) == ZONE_MOVABLE))
		gfp_mask \|= __GFP_HIGHMEM;

		if (!nodes_empty(nmask))
		new_page = __alloc_pages_nodemask(gfp_mask, 0,
		node_zonelist(nid, gfp_mask), &nmask);
		if (!new_page)

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