Re: [PATCH] mm: Remove PG_highmem description

From: Michal Hocko
Date: Wed Jan 31 2018 - 08:05:57 EST


On Wed 31-01-18 17:33:32, miles.chen@xxxxxxxxxxxx wrote:
> From: Miles Chen <miles.chen@xxxxxxxxxxxx>
>
> The commit cbe37d093707 ("[PATCH] mm: remove PG_highmem") has removed
> PG_highmem to save a page flag. So the description of PG_highmem
> is no longer needed, remove it.
>
> Signed-off-by: Miles Chen <miles.chen@xxxxxxxxxxxx>

Acked-by: Michal Hocko <mhocko@xxxxxxxx>

> ---
> include/linux/page-flags.h | 5 -----
> 1 file changed, 5 deletions(-)
>
> diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
> index 3ec44e27aa9d..50c2b8786831 100644
> --- a/include/linux/page-flags.h
> +++ b/include/linux/page-flags.h
> @@ -46,11 +46,6 @@
> * guarantees that this bit is cleared for a page when it first is entered into
> * the page cache.
> *
> - * PG_highmem pages are not permanently mapped into the kernel virtual address
> - * space, they need to be kmapped separately for doing IO on the pages. The
> - * struct page (these bits with information) are always mapped into kernel
> - * address space...
> - *
> * PG_hwpoison indicates that a page got corrupted in hardware and contains
> * data with incorrect ECC bits that triggered a machine check. Accessing is
> * not safe since it may cause another machine check. Don't touch!
> --
> 2.12.5
>

--
Michal Hocko
SUSE Labs