mm: move buddy list manipulations into helpers

In preparation for runtime randomization of the zone lists, take all
(well, most of) the list_*() functions in the buddy allocator and put
them in helper functions.  Provide a common control point for injecting
additional behavior when freeing pages.

[dan.j.williams@intel.com: fix buddy list helpers]
Link: http://lkml.kernel.org/r/155033679702.1773410.13041474192173212653.stgit@dwillia2-desk3.amr.corp.intel.com
[vbabka@suse.cz: remove del_page_from_free_area() migratetype parameter]
Link: http://lkml.kernel.org/r/4672701b-6775-6efd-0797-b6242591419e@suse.cz
Link: http://lkml.kernel.org/r/154899812264.3165233.5219320056406926223.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Robert Elliott <elliott@hpe.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 912614f..0e8834a 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -536,9 +536,6 @@ static inline void vma_set_anonymous(struct vm_area_struct *vma)
 struct mmu_gather;
 struct inode;
 
-#define page_private(page)             ((page)->private)
-#define set_page_private(page, v)      ((page)->private = (v))
-
 #if !defined(__HAVE_ARCH_PTE_DEVMAP) || !defined(CONFIG_TRANSPARENT_HUGEPAGE)
 static inline int pmd_devmap(pmd_t pmd)
 {

diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index e1f42a0..8ec38b1 100644 (file)
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -220,6 +220,9 @@ struct page {
 #define PAGE_FRAG_CACHE_MAX_SIZE       __ALIGN_MASK(32768, ~PAGE_MASK)
 #define PAGE_FRAG_CACHE_MAX_ORDER      get_order(PAGE_FRAG_CACHE_MAX_SIZE)
 
+#define page_private(page)             ((page)->private)
+#define set_page_private(page, v)      ((page)->private = (v))
+
 struct page_frag_cache {
        void * va;
 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 1fb5a04..acd6f9c 100644 (file)
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -18,6 +18,8 @@
 #include <linux/pageblock-flags.h>
 #include <linux/page-flags-layout.h>
 #include <linux/atomic.h>
+#include <linux/mm_types.h>
+#include <linux/page-flags.h>
 #include <asm/page.h>
 
 /* Free memory management - zoned buddy allocator.  */
@@ -98,6 +100,50 @@ struct free_area {
        unsigned long           nr_free;
 };
 
+/* Used for pages not on another list */
+static inline void add_to_free_area(struct page *page, struct free_area *area,
+                            int migratetype)
+{
+       list_add(&page->lru, &area->free_list[migratetype]);
+       area->nr_free++;
+}
+
+/* Used for pages not on another list */
+static inline void add_to_free_area_tail(struct page *page, struct free_area *area,
+                                 int migratetype)
+{
+       list_add_tail(&page->lru, &area->free_list[migratetype]);
+       area->nr_free++;
+}
+
+/* Used for pages which are on another list */
+static inline void move_to_free_area(struct page *page, struct free_area *area,
+                            int migratetype)
+{
+       list_move(&page->lru, &area->free_list[migratetype]);
+}
+
+static inline struct page *get_page_from_free_area(struct free_area *area,
+                                           int migratetype)
+{
+       return list_first_entry_or_null(&area->free_list[migratetype],
+                                       struct page, lru);
+}
+
+static inline void del_page_from_free_area(struct page *page,
+               struct free_area *area)
+{
+       list_del(&page->lru);
+       __ClearPageBuddy(page);
+       set_page_private(page, 0);
+       area->nr_free--;
+}
+
+static inline bool free_area_empty(struct free_area *area, int migratetype)
+{
+       return list_empty(&area->free_list[migratetype]);
+}
+
 struct pglist_data;
 
 /*

diff --git a/mm/compaction.c b/mm/compaction.c
index 6cc4bea..cbac727 100644 (file)
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1888,13 +1888,13 @@ static enum compact_result __compact_finished(struct compact_control *cc)
                bool can_steal;
 
                /* Job done if page is free of the right migratetype */
-               if (!list_empty(&area->free_list[migratetype]))
+               if (!free_area_empty(area, migratetype))
                        return COMPACT_SUCCESS;
 
 #ifdef CONFIG_CMA
                /* MIGRATE_MOVABLE can fallback on MIGRATE_CMA */
                if (migratetype == MIGRATE_MOVABLE &&
-                       !list_empty(&area->free_list[MIGRATE_CMA]))
+                       !free_area_empty(area, MIGRATE_CMA))
                        return COMPACT_SUCCESS;
 #endif
                /*

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 548f8f5..b674625 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -756,12 +756,6 @@ static inline void set_page_order(struct page *page, unsigned int order)
        __SetPageBuddy(page);
 }
 
-static inline void rmv_page_order(struct page *page)
-{
-       __ClearPageBuddy(page);
-       set_page_private(page, 0);
-}
-
 /*
  * This function checks whether a page is free && is the buddy
  * we can coalesce a page and its buddy if
@@ -919,13 +913,10 @@ continue_merging:
                 * Our buddy is free or it is CONFIG_DEBUG_PAGEALLOC guard page,
                 * merge with it and move up one order.
                 */
-               if (page_is_guard(buddy)) {
+               if (page_is_guard(buddy))
                        clear_page_guard(zone, buddy, order, migratetype);
-               } else {
-                       list_del(&buddy->lru);
-                       zone->free_area[order].nr_free--;
-                       rmv_page_order(buddy);
-               }
+               else
+                       del_page_from_free_area(buddy, &zone->free_area[order]);
                combined_pfn = buddy_pfn & pfn;
                page = page + (combined_pfn - pfn);
                pfn = combined_pfn;
@@ -975,15 +966,13 @@ done_merging:
                higher_buddy = higher_page + (buddy_pfn - combined_pfn);
                if (pfn_valid_within(buddy_pfn) &&
                    page_is_buddy(higher_page, higher_buddy, order + 1)) {
-                       list_add_tail(&page->lru,
-                               &zone->free_area[order].free_list[migratetype]);
-                       goto out;
+                       add_to_free_area_tail(page, &zone->free_area[order],
+                                             migratetype);
+                       return;
                }
        }
 
-       list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
-out:
-       zone->free_area[order].nr_free++;
+       add_to_free_area(page, &zone->free_area[order], migratetype);
 }
 
 /*
@@ -1974,8 +1963,7 @@ static inline void expand(struct zone *zone, struct page *page,
                if (set_page_guard(zone, &page[size], high, migratetype))
                        continue;
 
-               list_add(&page[size].lru, &area->free_list[migratetype]);
-               area->nr_free++;
+               add_to_free_area(&page[size], area, migratetype);
                set_page_order(&page[size], high);
        }
 }
@@ -2117,13 +2105,10 @@ struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
        /* Find a page of the appropriate size in the preferred list */
        for (current_order = order; current_order < MAX_ORDER; ++current_order) {
                area = &(zone->free_area[current_order]);
-               page = list_first_entry_or_null(&area->free_list[migratetype],
-                                                       struct page, lru);
+               page = get_page_from_free_area(area, migratetype);
                if (!page)
                        continue;
-               list_del(&page->lru);
-               rmv_page_order(page);
-               area->nr_free--;
+               del_page_from_free_area(page, area);
                expand(zone, page, order, current_order, area, migratetype);
                set_pcppage_migratetype(page, migratetype);
                return page;
@@ -2209,8 +2194,7 @@ static int move_freepages(struct zone *zone,
                }
 
                order = page_order(page);
-               list_move(&page->lru,
-                         &zone->free_area[order].free_list[migratetype]);
+               move_to_free_area(page, &zone->free_area[order], migratetype);
                page += 1 << order;
                pages_moved += 1 << order;
        }
@@ -2398,7 +2382,7 @@ static void steal_suitable_fallback(struct zone *zone, struct page *page,
 
 single_page:
        area = &zone->free_area[current_order];
-       list_move(&page->lru, &area->free_list[start_type]);
+       move_to_free_area(page, area, start_type);
 }
 
 /*
@@ -2422,7 +2406,7 @@ int find_suitable_fallback(struct free_area *area, unsigned int order,
                if (fallback_mt == MIGRATE_TYPES)
                        break;
 
-               if (list_empty(&area->free_list[fallback_mt]))
+               if (free_area_empty(area, fallback_mt))
                        continue;
 
                if (can_steal_fallback(order, migratetype))
@@ -2509,9 +2493,7 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
                for (order = 0; order < MAX_ORDER; order++) {
                        struct free_area *area = &(zone->free_area[order]);
 
-                       page = list_first_entry_or_null(
-                                       &area->free_list[MIGRATE_HIGHATOMIC],
-                                       struct page, lru);
+                       page = get_page_from_free_area(area, MIGRATE_HIGHATOMIC);
                        if (!page)
                                continue;
 
@@ -2634,8 +2616,7 @@ find_smallest:
        VM_BUG_ON(current_order == MAX_ORDER);
 
 do_steal:
-       page = list_first_entry(&area->free_list[fallback_mt],
-                                                       struct page, lru);
+       page = get_page_from_free_area(area, fallback_mt);
 
        steal_suitable_fallback(zone, page, alloc_flags, start_migratetype,
                                                                can_steal);
@@ -3072,6 +3053,7 @@ EXPORT_SYMBOL_GPL(split_page);
 
 int __isolate_free_page(struct page *page, unsigned int order)
 {
+       struct free_area *area = &page_zone(page)->free_area[order];
        unsigned long watermark;
        struct zone *zone;
        int mt;
@@ -3096,9 +3078,8 @@ int __isolate_free_page(struct page *page, unsigned int order)
        }
 
        /* Remove page from free list */
-       list_del(&page->lru);
-       zone->free_area[order].nr_free--;
-       rmv_page_order(page);
+
+       del_page_from_free_area(page, area);
 
        /*
         * Set the pageblock if the isolated page is at least half of a
@@ -3395,13 +3376,13 @@ bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
                        continue;
 
                for (mt = 0; mt < MIGRATE_PCPTYPES; mt++) {
-                       if (!list_empty(&area->free_list[mt]))
+                       if (!free_area_empty(area, mt))
                                return true;
                }
 
 #ifdef CONFIG_CMA
                if ((alloc_flags & ALLOC_CMA) &&
-                   !list_empty(&area->free_list[MIGRATE_CMA])) {
+                   !free_area_empty(area, MIGRATE_CMA)) {
                        return true;
                }
 #endif
@@ -5328,7 +5309,7 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
 
                        types[order] = 0;
                        for (type = 0; type < MIGRATE_TYPES; type++) {
-                               if (!list_empty(&area->free_list[type]))
+                               if (!free_area_empty(area, type))
                                        types[order] |= 1 << type;
                        }
                }
@@ -8501,9 +8482,7 @@ __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
                pr_info("remove from free list %lx %d %lx\n",
                        pfn, 1 << order, end_pfn);
 #endif
-               list_del(&page->lru);
-               rmv_page_order(page);
-               zone->free_area[order].nr_free--;
+               del_page_from_free_area(page, &zone->free_area[order]);
                for (i = 0; i < (1 << order); i++)
                        SetPageReserved((page+i));
                pfn += (1 << order);