From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with ESMTP id 250A46B024D for ; Fri, 9 Jul 2010 18:29:29 -0400 (EDT) Date: Fri, 9 Jul 2010 15:28:51 -0700 From: Andrew Morton Subject: Re: [PATCH v2 1/2] vmscan: don't subtraction of unsined Message-Id: <20100709152851.330bf2b2.akpm@linux-foundation.org> In-Reply-To: <20100709090956.CD51.A69D9226@jp.fujitsu.com> References: <20100708163401.CD34.A69D9226@jp.fujitsu.com> <20100708130048.fccfcdad.akpm@linux-foundation.org> <20100709090956.CD51.A69D9226@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: KOSAKI Motohiro Cc: LKML , linux-mm , Mel Gorman , Rik van Riel , Minchan Kim , Johannes Weiner List-ID: On Fri, 9 Jul 2010 10:16:33 +0900 (JST) KOSAKI Motohiro wrote: > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2588,7 +2588,7 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) > .swappiness = vm_swappiness, > .order = order, > }; > - unsigned long slab_reclaimable; > + unsigned long nr_slab_pages0, nr_slab_pages1; > > disable_swap_token(); > cond_resched(); > @@ -2615,8 +2615,8 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) > } while (priority >= 0 && sc.nr_reclaimed < nr_pages); > } > > - slab_reclaimable = zone_page_state(zone, NR_SLAB_RECLAIMABLE); > - if (slab_reclaimable > zone->min_slab_pages) { > + nr_slab_pages0 = zone_page_state(zone, NR_SLAB_RECLAIMABLE); > + if (nr_slab_pages0 > zone->min_slab_pages) { > /* > * shrink_slab() does not currently allow us to determine how > * many pages were freed in this zone. Well no, but it could do so, with some minor changes to struct reclaim_state and its handling. Put a zone* and a counter in reclaim_state, handle them in sl?b.c. > So we take the current > @@ -2628,16 +2628,17 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) > * take a long time. > */ > while (shrink_slab(sc.nr_scanned, gfp_mask, order) && > - zone_page_state(zone, NR_SLAB_RECLAIMABLE) > > - slab_reclaimable - nr_pages) > + (zone_page_state(zone, NR_SLAB_RECLAIMABLE) + nr_pages > > + nr_slab_pages0)) > ; > > /* > * Update nr_reclaimed by the number of slab pages we > * reclaimed from this zone. > */ > - sc.nr_reclaimed += slab_reclaimable - > - zone_page_state(zone, NR_SLAB_RECLAIMABLE); > + nr_slab_pages1 = zone_page_state(zone, NR_SLAB_RECLAIMABLE); > + if (nr_slab_pages1 < nr_slab_pages0) > + sc.nr_reclaimed += nr_slab_pages0 - nr_slab_pages1; My, that's horrible. The whole expression says "this number is basically a pile of random junk. Let's add it in anyway". > } > > p->reclaim_state = NULL; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org