Commit b95046b0 authored Sep 06, 2017 by Michal Hocko Committed by Linus Torvalds Sep 06, 2017

mm, sparse, page_ext: drop ugly N_HIGH_MEMORY branches for allocations

Commit f52407ce ("memory hotplug: alloc page from other node in
memory online") has introduced N_HIGH_MEMORY checks to only use NUMA
aware allocations when there is some memory present because the
respective node might not have any memory yet at the time and so it
could fail or even OOM.

Things have changed since then though.  Zonelists are now always
initialized before we do any allocations even for hotplug (see
959ecc48 ("mm/memory_hotplug.c: fix building of node hotplug
zonelist")).

Therefore these checks are not really needed.  In fact caller of the
allocator should never care about whether the node is populated because
that might change at any time.

Link: http://lkml.kernel.org/r/20170721143915.14161-10-mhocko@kernel.org


Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent b93e0f32

mm/page_ext.c

+1 −4

Original line number	Diff line number	Diff line
		@@ -222,10 +222,7 @@ static void *__meminit alloc_page_ext(size_t size, int nid)
		return addr;
		}

		if (node_state(nid, N_HIGH_MEMORY))
		addr = vzalloc_node(size, nid);
		else
		addr = vzalloc(size);

		return addr;
		}

mm/sparse-vmemmap.c

+3 −8

Original line number	Diff line number	Diff line
		@@ -54,12 +54,7 @@ void * __meminit vmemmap_alloc_block(unsigned long size, int node)
		if (slab_is_available()) {
		struct page *page;

		if (node_state(node, N_HIGH_MEMORY))
		page = alloc_pages_node(
		node, GFP_KERNEL \| __GFP_ZERO \| __GFP_RETRY_MAYFAIL,
		get_order(size));
		else
		page = alloc_pages(
		page = alloc_pages_node(node,
		GFP_KERNEL \| __GFP_ZERO \| __GFP_RETRY_MAYFAIL,
		get_order(size));
		if (page)

mm/sparse.c

+3 −7

Original line number	Diff line number	Diff line
		@@ -65,14 +65,10 @@ static noinline struct mem_section __ref *sparse_index_alloc(int nid)
		unsigned long array_size = SECTIONS_PER_ROOT *
		sizeof(struct mem_section);

		if (slab_is_available()) {
		if (node_state(nid, N_HIGH_MEMORY))
		if (slab_is_available())
		section = kzalloc_node(array_size, GFP_KERNEL, nid);
		else
		section = kzalloc(array_size, GFP_KERNEL);
		} else {
		section = memblock_virt_alloc_node(array_size, nid);
		}

		return section;
		}

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