The patch titled
Subject: page owners: correct page->order when to free page
has been removed from the -mm tree. Its filename was
page-owners-correct-page-order-when-to-free-page.patch
This patch was dropped because an alternative patch was merged
------------------------------------------------------
From: Jungsoo Son <jungsoo.son@xxxxxxx>
Subject: page owners: correct page->order when to free page
When I use PAGE_OWNER in mmotm tree, I found a problem that mismatches the
number of allocated pages. When I investigate, the problem is that
set_page_order is called for only a head page if freed page is merged to a
higher order page in the buddy allocator so tail pages of the higher order
page couldn't be reset to page->order = -1.
It means when we do 'cat /proc/page-owner', it could show wrong
information.
So page->order should be set to -1 for all the tail pages as well as the
first page before buddy allocator merges them.
This patch is for clearing page->order of all the tail pages in
free_pages_prepare() when to free page.
Signed-off-by: Jungsoo Son <jungsoo.son@xxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Acked-by: Minchan Kim <minchan@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 7 +++++++
1 file changed, 7 insertions(+)
diff -puN mm/page_alloc.c~page-owners-correct-page-order-when-to-free-page mm/page_alloc.c
--- a/mm/page_alloc.c~page-owners-correct-page-order-when-to-free-page
+++ a/mm/page_alloc.c
@@ -766,6 +766,13 @@ static bool free_pages_prepare(struct pa
if (bad)
return false;
+#ifdef CONFIG_PAGE_OWNER
+ for (i = 0; i < (1 << order); i++) {
+ struct page *p = (page + i);
+ p->order = -1;
+ }
+#endif
+
if (!PageHighMem(page)) {
debug_check_no_locks_freed(page_address(page),
PAGE_SIZE << order);
_
Patches currently in -mm which might be from jungsoo.son@xxxxxxx are
mm-page_ext-resurrect-struct-page-extending-code-for-debugging.patch
mm-debug-pagealloc-prepare-boottime-configurable-on-off.patch
mm-debug-pagealloc-make-debug-pagealloc-boottime-configurable.patch
mm-nommu-use-alloc_pages_exact-rather-than-its-own-implementation.patch
stacktrace-introduce-snprint_stack_trace-for-buffer-output.patch
mm-page_owner-keep-track-of-page-owners.patch
mm-page_owner-correct-owner-information-for-early-allocated-pages.patch
documentation-add-new-page_owner-document.patch
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