linux-kernel - Re: [PATCH 3/3] mm/page_owner: track page free call chain

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Date:	Sun, 3 Jul 2016 14:59:24 +0900
From:	Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>
To:	Sergey Senozhatsky <sergey.senozhatsky@...il.com>
Cc:	Joonsoo Kim <iamjoonsoo.kim@....com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Vlastimil Babka <vbabka@...e.cz>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org,
	Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>
Subject: Re: [PATCH 3/3] mm/page_owner: track page free call chain

On (07/03/16 01:16), Sergey Senozhatsky wrote:
[..]
> +#ifdef CONFIG_PAGE_OWNER_TRACK_FREE
> +void __page_owner_free_pages(struct page *page, unsigned int order)
> +{
> +	int i;
> +	depot_stack_handle_t handle;
> +	struct page_ext *page_ext = lookup_page_ext(page);
> +
> +	if (unlikely(!page_ext))
> +		return;
> +
> +	handle = save_stack(0);
> +	page_ext->handles[PAGE_OWNER_HANDLE_FREE] = handle;
> +	__set_bit(PAGE_EXT_OWNER_FREE, &page_ext->flags);
> +
> +	for (i = 1; i < (1 << order); i++) {
> +		struct page_ext *ext = lookup_page_ext(page + 1);
> +
> +		if (unlikely(!ext))
> +			continue;
> +		ext->handles[PAGE_OWNER_HANDLE_FREE] = handle;
> +		__set_bit(PAGE_EXT_OWNER_FREE, &ext->flags);
> +	}
> +}

I think this one is missing __clear_bit(PAGE_EXT_OWNER_ALLOC).

---
 mm/page_owner.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/page_owner.c b/mm/page_owner.c
index 5a108d6..699922c 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -154,6 +154,7 @@ void __page_owner_free_pages(struct page *page, unsigned int order)
 	handle = save_stack(0);
 	page_ext->handles[PAGE_OWNER_HANDLE_FREE] = handle;
 	__set_bit(PAGE_EXT_OWNER_FREE, &page_ext->flags);
+	__clear_bit(PAGE_EXT_OWNER_ALLOC, &page_ext->flags);
 
 	for (i = 1; i < (1 << order); i++) {
 		struct page_ext *ext = lookup_page_ext(page + 1);
@@ -162,6 +163,7 @@ void __page_owner_free_pages(struct page *page, unsigned int order)
 			continue;
 		ext->handles[PAGE_OWNER_HANDLE_FREE] = handle;
 		__set_bit(PAGE_EXT_OWNER_FREE, &ext->flags);
+		__clear_bit(PAGE_EXT_OWNER_ALLOC, &ext->flags);
 	}
 }
 #else
-- 
2.9.0.rc1