Re: [PATCH v3 09/12] mm: dump_page(): better diagnostics for huge pinned pages

[Kirill A. Shutemov]

On Fri, Jan 31, 2020 at 07:40:26PM -0800, John Hubbard wrote:
> As part of pin_user_pages() and related API calls, pages are
> "dma-pinned". For the case of compound pages of order > 1, the per-page
> accounting of dma pins is accomplished via the 3rd struct page in the
> compound page. In order to support debugging of any pin_user_pages()-
> related problems, enhance dump_page() so as to report the pin count
> in that case.
> 
> Documentation/core-api/pin_user_pages.rst is also updated accordingly.
> 
> Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>

Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>

-- 
 Kirill A. Shutemov