Subject: + mm-page_alloc-debug_vm-checks-for-free_list-placement-of-cma-and-reserve-pages.patch added to -mm tree
To: vbabka@xxxxxxx,b.zolnierkie@xxxxxxxxxxx,hughd@xxxxxxxxxx,iamjoonsoo.kim@xxxxxxx,kosaki.motohiro@xxxxxxxxxxxxxx,m.szyprowski@xxxxxxxxxxx,mgorman@xxxxxxx,mina86@xxxxxxxxxx,minchan@xxxxxxxxxx,riel@xxxxxxxxxx,ytk.lee@xxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Fri, 18 Apr 2014 15:10:51 -0700
The patch titled
Subject: mm/page_alloc: DEBUG_VM checks for free_list placement of CMA and RESERVE pages
has been added to the -mm tree. Its filename is
mm-page_alloc-debug_vm-checks-for-free_list-placement-of-cma-and-reserve-pages.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-page_alloc-debug_vm-checks-for-free_list-placement-of-cma-and-reserve-pages.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-page_alloc-debug_vm-checks-for-free_list-placement-of-cma-and-reserve-pages.patch
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------------------------------------------------------
From: Vlastimil Babka <vbabka@xxxxxxx>
Subject: mm/page_alloc: DEBUG_VM checks for free_list placement of CMA and RESERVE pages
For the MIGRATE_RESERVE pages, it is important they do not get misplaced
on free_list of other migratetype, otherwise the whole MIGRATE_RESERVE
pageblock might be changed to other migratetype in
try_to_steal_freepages(). For MIGRATE_CMA, the pages also must not go to
a different free_list, otherwise they could get allocated as unmovable and
result in CMA failure.
This is ensured by setting the freepage_migratetype appropriately when
placing pages on pcp lists, and using the information when releasing them
back to free_list. It is also assumed that CMA and RESERVE pageblocks are
created only in the init phase. This patch adds DEBUG_VM checks to catch
any regressions introduced for this invariant.
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Yong-Taek Lee <ytk.lee@xxxxxxxxxxx>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Michal Nazarewicz <mina86@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm.h | 19 +++++++++++++++++++
mm/page_alloc.c | 3 +++
2 files changed, 22 insertions(+)
diff -puN include/linux/mm.h~mm-page_alloc-debug_vm-checks-for-free_list-placement-of-cma-and-reserve-pages include/linux/mm.h
--- a/include/linux/mm.h~mm-page_alloc-debug_vm-checks-for-free_list-placement-of-cma-and-reserve-pages
+++ a/include/linux/mm.h
@@ -288,6 +288,25 @@ static inline int get_freepage_migratety
}
/*
+ * Check that a freepage cannot end up on a wrong free_list for "sensitive"
+ * migratetypes. Return false if it could. Useful for VM_BUG_ON checks.
+ */
+static inline bool check_freepage_migratetype(struct page *page)
+{
+ int pageblock_mt = get_pageblock_migratetype(page);
+ int freepage_mt = get_freepage_migratetype(page);
+
+ /*
+ * For RESERVE and CMA pageblocks, the freepage_migratetype must
+ * match their migratetype. For other pageblocks, we don't care.
+ */
+ if (pageblock_mt != MIGRATE_RESERVE && !is_migrate_cma(pageblock_mt))
+ return true;
+
+ return (freepage_mt == pageblock_mt);
+}
+
+/*
* FIXME: take this include out, include page-flags.h in
* files which need it (119 of them)
*/
diff -puN mm/page_alloc.c~mm-page_alloc-debug_vm-checks-for-free_list-placement-of-cma-and-reserve-pages mm/page_alloc.c
--- a/mm/page_alloc.c~mm-page_alloc-debug_vm-checks-for-free_list-placement-of-cma-and-reserve-pages
+++ a/mm/page_alloc.c
@@ -698,6 +698,8 @@ static void free_pcppages_bulk(struct zo
page = list_entry(list->prev, struct page, lru);
/* must delete as __free_one_page list manipulates */
list_del(&page->lru);
+
+ VM_BUG_ON(!check_freepage_migratetype(page));
mt = get_freepage_migratetype(page);
/* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
__free_one_page(page, zone, 0, mt);
@@ -1191,6 +1193,7 @@ static int rmqueue_bulk(struct zone *zon
struct page *page = __rmqueue(zone, order, migratetype);
if (unlikely(page == NULL))
break;
+ VM_BUG_ON(!check_freepage_migratetype(page));
/*
* Split buddy pages returned by expand() are received here
_
Patches currently in -mm which might be from vbabka@xxxxxxx are
thp-close-race-between-split-and-zap-huge-pages.patch
mm-compactionc-isolate_freepages_block-small-tuneup.patch
mm-page_alloc-prevent-migrate_reserve-pages-from-being-misplaced.patch
mm-page_alloc-debug_vm-checks-for-free_list-placement-of-cma-and-reserve-pages.patch
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