Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935258Ab0GPBkF (ORCPT ); Thu, 15 Jul 2010 21:40:05 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:39040 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935038Ab0GPBkC convert rfc822-to-8bit (ORCPT ); Thu, 15 Jul 2010 21:40:02 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: Andrew Morton Subject: Re: [PATCH v2 2/2] vmscan: shrink_slab() require number of lru_pages, not page order Cc: kosaki.motohiro@jp.fujitsu.com, Minchan Kim , Christoph Lameter , LKML , linux-mm , Mel Gorman , Rik van Riel , Johannes Weiner In-Reply-To: <20100715121551.bd5ccc61.akpm@linux-foundation.org> References: <20100713144008.EA52.A69D9226@jp.fujitsu.com> <20100715121551.bd5ccc61.akpm@linux-foundation.org> Message-Id: <20100716090302.7351.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 8BIT X-Mailer: Becky! ver. 2.50.07 [ja] Date: Fri, 16 Jul 2010 10:39:57 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3383 Lines: 92 > > 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 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 --- 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@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/