[PATCH v2 06/16] mm/page_alloc: Move set_page_refcounted() to callers of get_page_from_freelist()

["Matthew Wilcox (Oracle)" <willy@infradead.org>]

In preparation for allocating frozen pages, stop initialising the page
refcount in get_page_from_freelist().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 mm/page_alloc.c | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 9bc53001f56c..8c9102ab7a87 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4280,7 +4280,6 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
 				gfp_mask, alloc_flags, ac->migratetype);
 		if (page) {
 			prep_new_page(page, order, gfp_mask, alloc_flags);
-			set_page_refcounted(page);
 
 			/*
 			 * If this is a high-order atomic allocation then check
@@ -4374,6 +4373,8 @@ __alloc_pages_cpuset_fallback(gfp_t gfp_mask, unsigned int order,
 		page = get_page_from_freelist(gfp_mask, order,
 				alloc_flags, ac);
 
+	if (page)
+		set_page_refcounted(page);
 	return page;
 }
 
@@ -4412,8 +4413,10 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
 	page = get_page_from_freelist((gfp_mask | __GFP_HARDWALL) &
 				      ~__GFP_DIRECT_RECLAIM, order,
 				      ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac);
-	if (page)
+	if (page) {
+		set_page_refcounted(page);
 		goto out;
+	}
 
 	/* Coredumps can quickly deplete all memory reserves */
 	if (current->flags & PF_DUMPCORE)
@@ -4504,10 +4507,8 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
 	count_vm_event(COMPACTSTALL);
 
 	/* Prep a captured page if available */
-	if (page) {
+	if (page)
 		prep_new_page(page, order, gfp_mask, alloc_flags);
-		set_page_refcounted(page);
-	}
 
 	/* Try get a page from the freelist if available */
 	if (!page)
@@ -4516,6 +4517,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
 	if (page) {
 		struct zone *zone = page_zone(page);
 
+		set_page_refcounted(page);
 		zone->compact_blockskip_flush = false;
 		compaction_defer_reset(zone, order, true);
 		count_vm_event(COMPACTSUCCESS);
@@ -4765,6 +4767,7 @@ __alloc_pages_direct_reclaim(gfp_t gfp_mask, unsigned int order,
 		drained = true;
 		goto retry;
 	}
+	set_page_refcounted(page);
 out:
 	psi_memstall_leave(&pflags);
 
@@ -5058,8 +5061,10 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
 	 * that first
 	 */
 	page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
-	if (page)
+	if (page) {
+		set_page_refcounted(page);
 		goto got_pg;
+	}
 
 	/*
 	 * For costly allocations, try direct compaction first, as it's likely
@@ -5138,8 +5143,10 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
 
 	/* Attempt with potentially adjusted zonelist and alloc_flags */
 	page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
-	if (page)
+	if (page) {
+		set_page_refcounted(page);
 		goto got_pg;
+	}
 
 	/* Caller is not willing to reclaim, we can't balance anything */
 	if (!can_direct_reclaim)
@@ -5516,8 +5523,10 @@ struct page *__alloc_pages(gfp_t gfp, unsigned int order, int preferred_nid,
 
 	/* First allocation attempt */
 	page = get_page_from_freelist(alloc_gfp, order, alloc_flags, &ac);
-	if (likely(page))
+	if (likely(page)) {
+		set_page_refcounted(page);
 		goto out;
+	}
 
 	alloc_gfp = gfp;
 	ac.spread_dirty_pages = false;
-- 
2.35.1