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

Commit f52407ce2dea ("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
959ecc48fc75 ("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>

diff --git a/mm/page_ext.c b/mm/page_ext.c
index 88ccc044b09a41504fb212afdb5ca8a45e842998..714ce79256c541e25840aea71e3f9b071988562d 100644 (file)
--- a/mm/page_ext.c
+++ b/mm/page_ext.c
@@ -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);
+       addr = vzalloc_node(size, nid);
 
        return addr;
 }

diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
index c50b1a14d55ec0f36ae718f602216dd24d591a6b..d1a39b8051e01b9f979ad93b28bf0295d7a2cea3 100644 (file)
--- a/mm/sparse-vmemmap.c
+++ b/mm/sparse-vmemmap.c
@@ -54,14 +54,9 @@ 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(
-                               GFP_KERNEL | __GFP_ZERO | __GFP_RETRY_MAYFAIL,
-                               get_order(size));
+               page = alloc_pages_node(node,
+                       GFP_KERNEL | __GFP_ZERO | __GFP_RETRY_MAYFAIL,
+                       get_order(size));
                if (page)
                        return page_address(page);
                return NULL;

diff --git a/mm/sparse.c b/mm/sparse.c
index 7b4be3fd5cac074177b7f17ebdeb12dfa56d22e5..a9783acf2bb9c3caee10ff8cfd3a9228ac73b4a9 100644 (file)
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -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))
-                       section = kzalloc_node(array_size, GFP_KERNEL, nid);
-               else
-                       section = kzalloc(array_size, GFP_KERNEL);
-       } else {
+       if (slab_is_available())
+               section = kzalloc_node(array_size, GFP_KERNEL, nid);
+       else
                section = memblock_virt_alloc_node(array_size, nid);
-       }
 
        return section;
 }