mm/page_alloc: add an alloc_pages_bulk_array_node() helper

Patch series "vmalloc() vs bulk allocator", v2.

This patch (of 3):

Add a "node" variant of the alloc_pages_bulk_array() function.  The helper
guarantees that a __alloc_pages_bulk() is invoked with a valid NUMA node
ID.

Link: https://lkml.kernel.org/r/20210516202056.2120-1-urezki@gmail.com
Link: https://lkml.kernel.org/r/20210516202056.2120-2-urezki@gmail.comSigned-off-by: NUladzislau Rezki (Sony) <urezki@gmail.com>
Acked-by: NMel Gorman <mgorman@suse.de>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include/linux/gfp.h

@@ -536,6 +536,15 @@ alloc_pages_bulk_array(gfp_t gfp, unsigned long nr_pages, struct page **page_arr
 	return __alloc_pages_bulk(gfp, numa_mem_id(), NULL, nr_pages, NULL, page_array);
 }
 
+static inline unsigned long
+alloc_pages_bulk_array_node(gfp_t gfp, int nid, unsigned long nr_pages, struct page **page_array)
+{
+	if (nid == NUMA_NO_NODE)
+		nid = numa_mem_id();
+
+	return __alloc_pages_bulk(gfp, nid, NULL, nr_pages, NULL, page_array);
+}
+
 /*
  * Allocate pages, preferring the node given as nid. The node must be valid and
  * online. For more general interface, see alloc_pages_node().