Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965436Ab2B2JtO (ORCPT ); Wed, 29 Feb 2012 04:49:14 -0500 Received: from mail-bk0-f46.google.com ([209.85.214.46]:38080 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757158Ab2B2JtL convert rfc822-to-8bit (ORCPT ); Wed, 29 Feb 2012 04:49:11 -0500 MIME-Version: 1.0 In-Reply-To: <1329929337-16648-13-git-send-email-m.szyprowski@samsung.com> References: <1329929337-16648-1-git-send-email-m.szyprowski@samsung.com> <1329929337-16648-13-git-send-email-m.szyprowski@samsung.com> From: Barry Song <21cnbao@gmail.com> Date: Wed, 29 Feb 2012 17:48:49 +0800 Message-ID: Subject: Re: [Linaro-mm-sig] [PATCHv23 12/16] mm: trigger page reclaim in alloc_contig_range() to stabilise watermarks To: Marek Szyprowski Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org, linux-mm@kvack.org, linaro-mm-sig@lists.linaro.org, Ohad Ben-Cohen , Daniel Walker , Russell King , Arnd Bergmann , Jonathan Corbet , Mel Gorman , Michal Nazarewicz , Dave Hansen , Jesse Barker , Kyungmin Park , Andrew Morton , Rob Clark , KAMEZAWA Hiroyuki Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5194 Lines: 119 2012/2/23 Marek Szyprowski : > alloc_contig_range() performs memory allocation so it also should keep > track on keeping the correct level of memory watermarks. This commit adds > a call to *_slowpath style reclaim to grab enough pages to make sure that > the final collection of contiguous pages from freelists will not starve > the system. > > Signed-off-by: Marek Szyprowski > Signed-off-by: Kyungmin Park > CC: Michal Nazarewicz > Tested-by: Rob Clark > Tested-by: Ohad Ben-Cohen > Tested-by: Benjamin Gaignard > Tested-by: Robert Nelson > --- >  include/linux/mmzone.h |    9 +++++++ >  mm/page_alloc.c        |   62 ++++++++++++++++++++++++++++++++++++++++++++++++ >  2 files changed, 71 insertions(+), 0 deletions(-) > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > index 4781f30..77db8c0 100644 > --- a/include/linux/mmzone.h > +++ b/include/linux/mmzone.h > @@ -63,8 +63,10 @@ enum { > >  #ifdef CONFIG_CMA >  #  define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA) > +#  define cma_wmark_pages(zone)        zone->min_cma_pages >  #else >  #  define is_migrate_cma(migratetype) false > +#  define cma_wmark_pages(zone) 0 >  #endif > >  #define for_each_migratetype_order(order, type) \ > @@ -371,6 +373,13 @@ struct zone { >        /* see spanned/present_pages for more description */ >        seqlock_t               span_seqlock; >  #endif > +#ifdef CONFIG_CMA > +       /* > +        * CMA needs to increase watermark levels during the allocation > +        * process to make sure that the system is not starved. > +        */ > +       unsigned long           min_cma_pages; > +#endif >        struct free_area        free_area[MAX_ORDER]; > >  #ifndef CONFIG_SPARSEMEM > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 7a0d286..39cd74f 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -5092,6 +5092,11 @@ static void __setup_per_zone_wmarks(void) >                                        low + (min >> 2); >                zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) + >                                        low + (min >> 1); > + > +               zone->watermark[WMARK_MIN] += cma_wmark_pages(zone); > +               zone->watermark[WMARK_LOW] += cma_wmark_pages(zone); > +               zone->watermark[WMARK_HIGH] += cma_wmark_pages(zone); > + >                setup_zone_migrate_reserve(zone); >                spin_unlock_irqrestore(&zone->lock, flags); >        } > @@ -5695,6 +5700,56 @@ static int __alloc_contig_migrate_range(unsigned long start, unsigned long end) >        return ret > 0 ? 0 : ret; >  } > > +/* > + * Update zone's cma pages counter used for watermark level calculation. > + */ > +static inline void __update_cma_watermarks(struct zone *zone, int count) > +{ > +       unsigned long flags; > +       spin_lock_irqsave(&zone->lock, flags); > +       zone->min_cma_pages += count; > +       spin_unlock_irqrestore(&zone->lock, flags); > +       setup_per_zone_wmarks(); > +} > + > +/* > + * Trigger memory pressure bump to reclaim some pages in order to be able to > + * allocate 'count' pages in single page units. Does similar work as > + *__alloc_pages_slowpath() function. > + */ > +static int __reclaim_pages(struct zone *zone, gfp_t gfp_mask, int count) > +{ > +       enum zone_type high_zoneidx = gfp_zone(gfp_mask); > +       struct zonelist *zonelist = node_zonelist(0, gfp_mask); > +       int did_some_progress = 0; > +       int order = 1; > +       unsigned long watermark; > + > +       /* > +        * Increase level of watermarks to force kswapd do his job > +        * to stabilise at new watermark level. > +        */ > +       __update_cma_watermarks(zone, count); > + > +       /* Obey watermarks as if the page was being allocated */ > +       watermark = low_wmark_pages(zone) + count; > +       while (!zone_watermark_ok(zone, 0, watermark, 0, 0)) { > +               wake_all_kswapd(order, zonelist, high_zoneidx, zone_idx(zone)); > + > +               did_some_progress = __perform_reclaim(gfp_mask, order, zonelist, > +                                                     NULL); > +               if (!did_some_progress) { > +                       /* Exhausted what can be done so it's blamo time */ > +                       out_of_memory(zonelist, gfp_mask, order, NULL); out_of_memory() has got another param in the newest next/master tree, out_of_memory(zonelist, gfp_mask, order, NULL, false) should be OK. -barry -- 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/