Re: [PATCHv2, RFC 11/30] thp, mm: handle tail pages in page_cache_get_speculative()

[Ric Mason]

Hi Kirill,
On 03/15/2013 01:50 AM, Kirill A. Shutemov wrote:
> From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
>
> For tail page we call __get_page_tail(). It has the same semantics, but
> for tail page.
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> ---
>   include/linux/pagemap.h |    4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
> index 3521b0d..408c4e3 100644
> --- a/include/linux/pagemap.h
> +++ b/include/linux/pagemap.h
> @@ -159,6 +159,9 @@ static inline int page_cache_get_speculative(struct page *page)

What's the different between page_cache_get_speculative and page_cache_get?

>   {
>   	VM_BUG_ON(in_interrupt());
>   
> +	if (unlikely(PageTail(page)))
> +		return __get_page_tail(page);
> +
>   #ifdef CONFIG_TINY_RCU
>   # ifdef CONFIG_PREEMPT_COUNT
>   	VM_BUG_ON(!in_atomic());
> @@ -185,7 +188,6 @@ static inline int page_cache_get_speculative(struct page *page)
>   		return 0;
>   	}
>   #endif
> -	VM_BUG_ON(PageTail(page));
>   
>   	return 1;
>   }

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/