On (20/08/07 14:50), Christoph Lameter didst pronounce:
> Direct reclaim collects a global laundry list in try_to_free_pages().
>
> Pages are only written back after a reclaim pass is complete.
>
> Signed-off-by: Christoph Lameter <[EMAIL PROTECTED]>
>
> ---
> mm/vmscan.c | 12 +++++++++---
> 1 file changed, 9 insertions(+), 3 deletions(-)
>
> Index: linux-2.6/mm/vmscan.c
> ===================================================================
> --- linux-2.6.orig/mm/vmscan.c 2007-08-19 23:30:15.000000000 -0700
> +++ linux-2.6/mm/vmscan.c 2007-08-19 23:53:43.000000000 -0700
> @@ -1099,7 +1099,7 @@ static unsigned long shrink_zone(int pri
> * scan then give up on it.
> */
> static unsigned long shrink_zones(int priority, struct zone **zones,
> - struct scan_control *sc)
> + struct scan_control *sc, struct list_head *laundry)
> {
> unsigned long nr_reclaimed = 0;
> int i;
> @@ -1121,7 +1121,7 @@ static unsigned long shrink_zones(int pr
>
> sc->all_unreclaimable = 0;
>
> - nr_reclaimed += shrink_zone(priority, zone, sc, NULL);
> + nr_reclaimed += shrink_zone(priority, zone, sc, laundry);
> }
> return nr_reclaimed;
> }
> @@ -1156,6 +1156,7 @@ unsigned long try_to_free_pages(struct z
> .swappiness = vm_swappiness,
> .order = order,
> };
> + LIST_HEAD(laundry);
>
> count_vm_event(ALLOCSTALL);
>
> @@ -1170,16 +1171,19 @@ unsigned long try_to_free_pages(struct z
> }
>
> for (priority = DEF_PRIORITY; priority >= 0; priority--) {
> +
> sc.nr_scanned = 0;
> if (!priority)
> disable_swap_token();
> - nr_reclaimed += shrink_zones(priority, zones, &sc);
> + nr_reclaimed += shrink_zones(priority, zones, &sc, &laundry);
> shrink_slab(sc.nr_scanned, gfp_mask, lru_pages);
> if (reclaim_state) {
> nr_reclaimed += reclaim_state->reclaimed_slab;
> reclaim_state->reclaimed_slab = 0;
> }
> +
> total_scanned += sc.nr_scanned;
> +
Could this not isolate a load of dirty pages on the laundry list and then
shortly later go to sleep in congestion_wait() ? It would appear that with
writeout deferred that the going to sleep is going to do nothing to help
the situation.
> if (nr_reclaimed >= sc.swap_cluster_max) {
> ret = 1;
> goto out;
> @@ -1223,6 +1227,8 @@ out:
>
> zone->prev_priority = priority;
> }
> + nr_reclaimed += shrink_page_list(&laundry, &sc, NULL);
> + release_lru_pages(&laundry);
> return ret;
> }
>
--
Mel Gorman
Part-time Phd Student Linux Technology Center
University of Limerick IBM Dublin Software Lab
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
