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From:   Zhaoyang Huang <huangzhaoyang@gmail.com>
Date:   Thu, 10 Feb 2022 18:00:59 +0800
Message-ID: <CAGWkznFei0igVSRRsSHuC+dnu6PFHrQJ1kjJFE+qEV1c2c1prA@mail.gmail.com>
Subject: Re: [RFC PATCH] mm: record context on page->mapping
To:     Andrew Morton <akpm@linux-foundation.org>,
        Zhaoyang Huang <zhaoyang.huang@unisoc.com>,
        "open list:MEMORY MANAGEMENT" <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>
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There are some places to modify as 'free_pages_check' for the formal
version, just RFC here to see if it is doable?

On Thu, Feb 10, 2022 at 5:02 PM Huangzhaoyang <huangzhaoyang@gmail.com> wrote:
>
> From: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
>
> Since page->mapping is vacant in the pages which used by kernel(drivers etc)
> Have it record current context to help tracking the page's owner in system
> memory dump.
>
> Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
> ---
>  mm/page_alloc.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index c595274..2757d10 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -2430,6 +2430,8 @@ static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags
>                 set_page_pfmemalloc(page);
>         else
>                 clear_page_pfmemalloc(page);
> +
> +       page->mapping = (struct address_space *)current;
>  }
>
>  /*
> --
> 1.9.1
>