mm/page_alloc: combine __alloc_pages and __alloc_pages_nodemask

There are only two callers of __alloc_pages() so prune the thicket of
alloc_page variants by combining the two functions together.  Current
callers of __alloc_pages() simply add an extra 'NULL' parameter and
current callers of __alloc_pages_nodemask() call __alloc_pages() instead.

Link: https://lkml.kernel.org/r/20210225150642.2582252-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Author: Matthew Wilcox (Oracle)

Documentation/admin-guide/mm/transhuge.rst

@@ -402,7 +402,7 @@ compact_fail
 	but failed.
 
 It is possible to establish how long the stalls were using the function
-tracer to record how long was spent in __alloc_pages_nodemask and
+tracer to record how long was spent in __alloc_pages() and
 using the mm_page_alloc tracepoint to identify which allocations were
 for huge pages.
 

include/linux/gfp.h

@@ -515,15 +515,8 @@ static inline int arch_make_page_accessible(struct page *page)
 }
 #endif
 
-struct page *
-__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int preferred_nid,
-							nodemask_t *nodemask);
-
-static inline struct page *
-__alloc_pages(gfp_t gfp_mask, unsigned int order, int preferred_nid)
-{
-	return __alloc_pages_nodemask(gfp_mask, order, preferred_nid, NULL);
-}
+struct page *__alloc_pages(gfp_t gfp, unsigned int order, int preferred_nid,
+		nodemask_t *nodemask);
 
 /*
  * Allocate pages, preferring the node given as nid. The node must be valid and
@@ -535,7 +528,7 @@ __alloc_pages_node(int nid, gfp_t gfp_mask, unsigned int order)
 	VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES);
 	VM_WARN_ON((gfp_mask & __GFP_THISNODE) && !node_online(nid));
 
-	return __alloc_pages(gfp_mask, order, nid);
+	return __alloc_pages(gfp_mask, order, nid, NULL);
 }
 
 /*

mm/hugetlb.c

@@ -1616,7 +1616,7 @@ static struct page *alloc_buddy_huge_page(struct hstate *h,
 		gfp_mask |= __GFP_RETRY_MAYFAIL;
 	if (nid == NUMA_NO_NODE)
 		nid = numa_mem_id();
-	page = __alloc_pages_nodemask(gfp_mask, order, nid, nmask);
+	page = __alloc_pages(gfp_mask, order, nid, nmask);
 	if (page)
 		__count_vm_event(HTLB_BUDDY_PGALLOC);
 	else

mm/internal.h

@@ -145,10 +145,10 @@ extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
  * family of functions.
  *
  * nodemask, migratetype and highest_zoneidx are initialized only once in
- * __alloc_pages_nodemask() and then never change.
+ * __alloc_pages() and then never change.
  *
  * zonelist, preferred_zone and highest_zoneidx are set first in
- * __alloc_pages_nodemask() for the fast path, and might be later changed
+ * __alloc_pages() for the fast path, and might be later changed
  * in __alloc_pages_slowpath(). All other functions pass the whole structure
  * by a const pointer.
  */

mm/mempolicy.c

@@ -2140,7 +2140,7 @@ static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,
 {
 	struct page *page;
 
-	page = __alloc_pages(gfp, order, nid);
+	page = __alloc_pages(gfp, order, nid, NULL);
 	/* skip NUMA_INTERLEAVE_HIT counter update if numa stats is disabled */
 	if (!static_branch_likely(&vm_numa_stat_key))
 		return page;
@@ -2237,7 +2237,7 @@ alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma,
 
 	nmask = policy_nodemask(gfp, pol);
 	preferred_nid = policy_node(gfp, pol, node);
-	page = __alloc_pages_nodemask(gfp, order, preferred_nid, nmask);
+	page = __alloc_pages(gfp, order, preferred_nid, nmask);
 	mpol_cond_put(pol);
 out:
 	return page;
@@ -2274,7 +2274,7 @@ struct page *alloc_pages_current(gfp_t gfp, unsigned order)
 	if (pol->mode == MPOL_INTERLEAVE)
 		page = alloc_page_interleave(gfp, order, interleave_nodes(pol));
 	else
-		page = __alloc_pages_nodemask(gfp, order,
+		page = __alloc_pages(gfp, order,
 				policy_node(gfp, pol, numa_node_id()),
 				policy_nodemask(gfp, pol));
 

mm/migrate.c

@@ -1617,7 +1617,7 @@ struct page *alloc_migration_target(struct page *page, unsigned long private)
 	if (is_highmem_idx(zidx) || zidx == ZONE_MOVABLE)
 		gfp_mask |= __GFP_HIGHMEM;
 
-	new_page = __alloc_pages_nodemask(gfp_mask, order, nid, mtc->nmask);
+	new_page = __alloc_pages(gfp_mask, order, nid, mtc->nmask);
 
 	if (new_page && PageTransHuge(new_page))
 		prep_transhuge_page(new_page);

mm/page_alloc.c

@@ -5013,8 +5013,7 @@ static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order,
 /*
  * This is the 'heart' of the zoned buddy allocator.
  */
-struct page *
-__alloc_pages_nodemask(gfp_t gfp, unsigned int order, int preferred_nid,
+struct page *__alloc_pages(gfp_t gfp, unsigned int order, int preferred_nid,
 							nodemask_t *nodemask)
 {
 	struct page *page;
@@ -5076,7 +5075,7 @@ __alloc_pages_nodemask(gfp_t gfp, unsigned int order, int preferred_nid,
 
 	return page;
 }
-EXPORT_SYMBOL(__alloc_pages_nodemask);
+EXPORT_SYMBOL(__alloc_pages);
 
 /*
  * Common helper functions. Never use with __GFP_HIGHMEM because the returned