Re: [PATCH 04/33] readahead: page flag PG_readahead

Peter Zijlstra
2006-05-24T12:27:52Z

On Wed, 2006-05-24 at 19:12 +0800, Wu Fengguang wrote:
> plain text document attachment
> (readahead-page-flag-PG_readahead.patch)
> An new page flag PG_readahead is introduced as a look-ahead mark, which
> reminds the caller to give the adaptive read-ahead logic a chance to do
> read-ahead ahead of time for I/O pipelining.
>
> It roughly corresponds to `ahead_start' of the stock read-ahead logic.
>
> Signed-off-by: Wu Fengguang <wfg@mail.ustc.edu.cn>
> ---
>
> include/linux/page-flags.h | 5 +++++
> mm/page_alloc.c | 2 +-
> 2 files changed, 6 insertions(+), 1 deletion(-)
>
> --- linux-2.6.17-rc4-mm3.orig/include/linux/page-flags.h
> +++ linux-2.6.17-rc4-mm3/include/linux/page-flags.h
> @@ -89,6 +89,7 @@
> #define PG_reclaim 17 /* To be reclaimed asap */
> #define PG_nosave_free 18 /* Free, should not be written */
> #define PG_buddy 19 /* Page is free, on buddy lists */
> +#define PG_readahead 20 /* Reminder to do readahead */
>

Page flags are gouped by four, 20 would start a new set.
Also in my tree (git from a few days ago), 20 is taken by PG_unchached.
What code is this patch-set against?