On Mon 08-08-11 15:02:07, Konstantin Khlebnikov wrote:
> LRU scanning order was accidentially changed in commit v2.6.27-5584-gb69408e:
> "vmscan: Use an indexed array for LRU variables".
> Before that commit reclaimer always scan active lists first.
>
> This patch just reverse it back.
I am still not sure I see why the ordering matters that much.
One thing that might matter is that shrink_list moves some pages from
active to inactive list if inactive is low so it makes sense to try to
shrink active before inactive. It would be a problem if inactive was
almost empty. Then we would just waste time by shrinking inactive first.
I am not sure how real problem is that, though.
Whatever is the reason, I think it should be documented in the
changelog.
The change makes sense to me.
>
> Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxx>
> ---
> include/linux/mmzone.h | 3 ++-
> 1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> index be1ac8d..0094389 100644
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -141,7 +141,8 @@ enum lru_list {
>
> #define for_each_lru(l) for (l = 0; l < NR_LRU_LISTS; l++)
>
> -#define for_each_evictable_lru(l) for (l = 0; l <= LRU_ACTIVE_FILE; l++)
> +#define for_each_evictable_lru(l) \
> + for (l = LRU_ACTIVE_FILE; (int)l >= LRU_INACTIVE_ANON; l--)
>
> static inline int is_file_lru(enum lru_list l)
> {
>
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SUSE Labs
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