On Tue, Aug 07, 2012 at 01:31:14PM +0100, Mel Gorman wrote:
> When direct reclaim is running reclaim/compaction, there is a minimum
> number of pages it reclaims. As it must be under the low watermark to be
> in direct reclaim it has also woken kswapd to do some work. This patch
> has kswapd use the same logic as direct reclaim to reclaim a minimum
> number of pages so compaction can run later.
-ENOPARSE by my stupid brain.
Could you elaborate a bit more?
>
> Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
> ---
> mm/vmscan.c | 19 ++++++++++++++++---
> 1 file changed, 16 insertions(+), 3 deletions(-)
>
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 0cb2593..afdec93 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -1701,7 +1701,7 @@ static bool in_reclaim_compaction(struct scan_control *sc)
> * calls try_to_compact_zone() that it will have enough free pages to succeed.
> * It will give up earlier than that if there is difficulty reclaiming pages.
> */
> -static inline bool should_continue_reclaim(struct lruvec *lruvec,
> +static bool should_continue_reclaim(struct lruvec *lruvec,
> unsigned long nr_reclaimed,
> unsigned long nr_scanned,
> struct scan_control *sc)
> @@ -1768,6 +1768,17 @@ static inline bool should_continue_reclaim(struct lruvec *lruvec,
> }
> }
>
> +static inline bool should_continue_reclaim_zone(struct zone *zone,
> + unsigned long nr_reclaimed,
> + unsigned long nr_scanned,
> + struct scan_control *sc)
> +{
> + struct mem_cgroup *memcg = mem_cgroup_iter(NULL, NULL, NULL);
> + struct lruvec *lruvec = mem_cgroup_zone_lruvec(zone, memcg);
> +
> + return should_continue_reclaim(lruvec, nr_reclaimed, nr_scanned, sc);
> +}
> +
> /*
> * This is a basic per-zone page freer. Used by both kswapd and direct reclaim.
> */
> @@ -2496,8 +2507,10 @@ loop_again:
> */
> testorder = order;
> if (COMPACTION_BUILD && order &&
> - compaction_suitable(zone, order) !=
> - COMPACT_SKIPPED)
> + !should_continue_reclaim_zone(zone,
> + nr_soft_reclaimed,
nr_soft_reclaimed is always zero with !CONFIG_MEMCG.
So should_continue_reclaim_zone would return normally true in case of
non-__GFP_REPEAT allocation. Is it intentional?
> + sc.nr_scanned - nr_soft_scanned,
> + &sc))
> testorder = 0;
>
> if ((buffer_heads_over_limit && is_highmem_idx(i)) ||
> --
> 1.7.9.2
>
> --
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--
Kind regards,
Minchan Kim
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