mm/page_alloc: introduce post allocation processing on page allocator

This patch is motivated from Hugh and Vlastimil's concern [1].

There are two ways to get freepage from the allocator.  One is using
normal memory allocation API and the other is __isolate_free_page()
which is internally used for compaction and pageblock isolation.  Later
usage is rather tricky since it doesn't do whole post allocation
processing done by normal API.

One problematic thing I already know is that poisoned page would not be
checked if it is allocated by __isolate_free_page().  Perhaps, there
would be more.

We could add more debug logic for allocated page in the future and this
separation would cause more problem.  I'd like to fix this situation at
this time.  Solution is simple.  This patch commonize some logic for
newly allocated page and uses it on all sites.  This will solve the
problem.

[1] http://marc.info/?i=alpine.LSU.2.11.1604270029350.7066%40eggly.anvils%3E

[[email protected]: mm-page_alloc-introduce-post-allocation-processing-on-page-allocator-v3]
  Link: http://lkml.kernel.org/r/[email protected]
  Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Joonsoo Kim <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Michal Hocko <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

mm/compaction.c

@@ -74,14 +74,8 @@ static void map_pages(struct list_head *list)
 
 		order = page_private(page);
 		nr_pages = 1 << order;
-		set_page_private(page, 0);
-		set_page_refcounted(page);
 
-		arch_alloc_page(page, order);
-		kernel_map_pages(page, nr_pages, 1);
-		kasan_alloc_pages(page, order);
-
-		set_page_owner(page, order, __GFP_MOVABLE);
+		post_alloc_hook(page, order, __GFP_MOVABLE);
 		if (order)
 			split_page(page, order);
 

mm/internal.h

@@ -150,6 +150,8 @@ extern int __isolate_free_page(struct page *page, unsigned int order);
 extern void __free_pages_bootmem(struct page *page, unsigned long pfn,
 					unsigned int order);
 extern void prep_compound_page(struct page *page, unsigned int order);
+extern void post_alloc_hook(struct page *page, unsigned int order,
+					gfp_t gfp_flags);
 extern int user_min_free_kbytes;
 
 #if defined CONFIG_COMPACTION || defined CONFIG_CMA

mm/page_alloc.c

@@ -1724,6 +1724,19 @@ static bool check_new_pages(struct page *page, unsigned int order)
 	return false;
 }
 
+inline void post_alloc_hook(struct page *page, unsigned int order,
+				gfp_t gfp_flags)
+{
+	set_page_private(page, 0);
+	set_page_refcounted(page);
+
+	arch_alloc_page(page, order);
+	kernel_map_pages(page, 1 << order, 1);
+	kernel_poison_pages(page, 1 << order, 1);
+	kasan_alloc_pages(page, order);
+	set_page_owner(page, order, gfp_flags);
+}
+
 static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,
 							unsigned int alloc_flags)
 {
@@ -1736,13 +1749,7 @@ static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags
 			poisoned &= page_is_poisoned(p);
 	}
 
-	set_page_private(page, 0);
-	set_page_refcounted(page);
-
-	arch_alloc_page(page, order);
-	kernel_map_pages(page, 1 << order, 1);
-	kernel_poison_pages(page, 1 << order, 1);
-	kasan_alloc_pages(page, order);
+	post_alloc_hook(page, order, gfp_flags);
 
 	if (!free_pages_prezeroed(poisoned) && (gfp_flags & __GFP_ZERO))
 		for (i = 0; i < (1 << order); i++)
@@ -1751,8 +1758,6 @@ static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags
 	if (order && (gfp_flags & __GFP_COMP))
 		prep_compound_page(page, order);
 
-	set_page_owner(page, order, gfp_flags);
-
 	/*
 	 * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to
 	 * allocate the page. The expectation is that the caller is taking

mm/page_isolation.c

@@ -128,9 +128,7 @@ static void unset_migratetype_isolate(struct page *page, unsigned migratetype)
 out:
 	spin_unlock_irqrestore(&zone->lock, flags);
 	if (isolated_page) {
-		kernel_map_pages(page, (1 << order), 1);
-		set_page_refcounted(page);
-		set_page_owner(page, order, __GFP_MOVABLE);
+		post_alloc_hook(page, order, __GFP_MOVABLE);
 		__free_pages(isolated_page, order);
 	}
 }