mm/page_owner: set correct gfp_mask on page_owner

Currently, we set wrong gfp_mask to page_owner info in case of isolated
freepage by compaction and split page.  It causes incorrect mixed
pageblock report that we can get from '/proc/pagetypeinfo'.  This metric
is really useful to measure fragmentation effect so should be accurate.
This patch fixes it by setting correct information.

Without this patch, after kernel build workload is finished, number of
mixed pageblock is 112 among roughly 210 movable pageblocks.

But, with this fix, output shows that mixed pageblock is just 57.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/page_owner.h b/include/linux/page_owner.h
index b48c3471c254471ed940921ab7bb4832d6f92023..cacaabea8a0950115138c956737c2bd9d7c04a90 100644 (file)
--- a/include/linux/page_owner.h
+++ b/include/linux/page_owner.h
@@ -8,6 +8,7 @@ extern struct page_ext_operations page_owner_ops;
 extern void __reset_page_owner(struct page *page, unsigned int order);
 extern void __set_page_owner(struct page *page,
                        unsigned int order, gfp_t gfp_mask);
+extern gfp_t __get_page_owner_gfp(struct page *page);
 
 static inline void reset_page_owner(struct page *page, unsigned int order)
 {
@@ -25,6 +26,14 @@ static inline void set_page_owner(struct page *page,
 
        __set_page_owner(page, order, gfp_mask);
 }
+
+static inline gfp_t get_page_owner_gfp(struct page *page)
+{
+       if (likely(!page_owner_inited))
+               return 0;
+
+       return __get_page_owner_gfp(page);
+}
 #else
 static inline void reset_page_owner(struct page *page, unsigned int order)
 {
@@ -33,6 +42,10 @@ static inline void set_page_owner(struct page *page,
                        unsigned int order, gfp_t gfp_mask)
 {
 }
+static inline gfp_t get_page_owner_gfp(struct page *page)
+{
+       return 0;
+}
 
 #endif /* CONFIG_PAGE_OWNER */
 #endif /* __LINUX_PAGE_OWNER_H */

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index fbba675a0bd9e6f4337ab5e6eab46ba378f1e013..ef19f22b2b7de1728fb4ed8d6451d29bb993a928 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1948,6 +1948,7 @@ void free_hot_cold_page_list(struct list_head *list, bool cold)
 void split_page(struct page *page, unsigned int order)
 {
        int i;
+       gfp_t gfp_mask;
 
        VM_BUG_ON_PAGE(PageCompound(page), page);
        VM_BUG_ON_PAGE(!page_count(page), page);
@@ -1961,10 +1962,11 @@ void split_page(struct page *page, unsigned int order)
                split_page(virt_to_page(page[0].shadow), order);
 #endif
 
-       set_page_owner(page, 0, 0);
+       gfp_mask = get_page_owner_gfp(page);
+       set_page_owner(page, 0, gfp_mask);
        for (i = 1; i < (1 << order); i++) {
                set_page_refcounted(page + i);
-               set_page_owner(page + i, 0, 0);
+               set_page_owner(page + i, 0, gfp_mask);
        }
 }
 EXPORT_SYMBOL_GPL(split_page);
@@ -1994,7 +1996,7 @@ int __isolate_free_page(struct page *page, unsigned int order)
        zone->free_area[order].nr_free--;
        rmv_page_order(page);
 
-       set_page_owner(page, order, 0);
+       set_page_owner(page, order, __GFP_MOVABLE);
 
        /* Set the pageblock if the isolated page is at least a pageblock */
        if (order >= pageblock_order - 1) {

diff --git a/mm/page_owner.c b/mm/page_owner.c
index bd5f842b56d26aca3cf24225884d5a2eacd1580c..983c3a10fa07058df249c64d5c89b9578661f672 100644 (file)
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -76,6 +76,13 @@ void __set_page_owner(struct page *page, unsigned int order, gfp_t gfp_mask)
        __set_bit(PAGE_EXT_OWNER, &page_ext->flags);
 }
 
+gfp_t __get_page_owner_gfp(struct page *page)
+{
+       struct page_ext *page_ext = lookup_page_ext(page);
+
+       return page_ext->gfp_mask;
+}
+
 static ssize_t
 print_page_owner(char __user *buf, size_t count, unsigned long pfn,
                struct page *page, struct page_ext *page_ext)