vmscan: shrink_slab() require number of lru_pages, not page order
in [Kernel]
|
Prev: [PATCH 2/6] perf ui: Introduce routine ui_browser__is_current_entry
Next: vmscan: zone_reclaim don't call disable_swap_token()
From: KOSAKI Motohiro on 15 Jul 2010 21:50 > > nr_slab_pages0 = zone_page_state(zone, NR_SLAB_RECLAIMABLE); > > if (nr_slab_pages0 > zone->min_slab_pages) { > > + unsigned long lru_pages = zone_reclaimable_pages(zone); > > + > > /* > > * shrink_slab() does not currently allow us to determine how > > * many pages were freed in this zone. So we take the current > > @@ -2622,7 +2624,7 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) > > * Note that shrink_slab will free memory on all zones and may > > * take a long time. > > */ > > - while (shrink_slab(sc.nr_scanned, gfp_mask, order) && > > + while (shrink_slab(sc.nr_scanned, gfp_mask, lru_pages) && > > (zone_page_state(zone, NR_SLAB_RECLAIMABLE) + nr_pages > > > nr_slab_pages0)) > > ; > > Wouldn't it be better to recalculate zone_reclaimable_pages() each time > around the loop? For example, shrink_icache_memory()->prune_icache() > will remove pagecache from an inode if it hits the tail of the list. > This can change the number of reclaimable pages by squigabytes, but > this code thinks nothing changed? Ah, I missed this. incrementa patch is here. thank you! From 8f7c70cfb4a25f8292a59564db6c3ff425a69b53 Mon Sep 17 00:00:00 2001 From: KOSAKI Motohiro <kosaki.motohiro(a)jp.fujitsu.com> Date: Fri, 16 Jul 2010 08:40:01 +0900 Subject: [PATCH] vmscan: recalculate lru_pages on each shrink_slab() Andrew Morton pointed out shrink_slab() may change number of reclaimable pages (e.g. shrink_icache_memory()->prune_icache() will remove unmapped pagecache). So, we need to recalculate lru_pages on each shrink_slab() calling. This patch fixes it. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro(a)jp.fujitsu.com> --- mm/vmscan.c | 18 ++++++++++++------ 1 files changed, 12 insertions(+), 6 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 1bf9f72..1da9b14 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2612,8 +2612,6 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) nr_slab_pages0 = zone_page_state(zone, NR_SLAB_RECLAIMABLE); if (nr_slab_pages0 > zone->min_slab_pages) { - unsigned long lru_pages = zone_reclaimable_pages(zone); - /* * shrink_slab() does not currently allow us to determine how * many pages were freed in this zone. So we take the current @@ -2624,10 +2622,18 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) * Note that shrink_slab will free memory on all zones and may * take a long time. */ - while (shrink_slab(sc.nr_scanned, gfp_mask, lru_pages) && - (zone_page_state(zone, NR_SLAB_RECLAIMABLE) + nr_pages > - nr_slab_pages0)) - ; + for (;;) { + unsigned long lru_pages = zone_reclaimable_pages(zone); + + /* No reclaimable slab or very low memroy pressure */ + if (!shrink_slab(sc.nr_scanned, gfp_mask, lru_pages)) + break; + + /* Freed enouch memory */ + nr_slab_pages1 = zone_page_state(zone, NR_SLAB_RECLAIMABLE); + if (nr_slab_pages1 + nr_pages <= nr_slab_pages0) + break; + } /* * Update nr_reclaimed by the number of slab pages we -- 1.6.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |