From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030979AbeCANpP (ORCPT ); Thu, 1 Mar 2018 08:45:15 -0500 Received: from mx2.suse.de ([195.135.220.15]:59538 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030801AbeCANpO (ORCPT ); Thu, 1 Mar 2018 08:45:14 -0500 Date: Thu, 1 Mar 2018 14:45:12 +0100 From: Michal Hocko To: Aaron Lu Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Huang Ying , Dave Hansen , Kemi Wang , Tim Chen , Andi Kleen , Vlastimil Babka , Mel Gorman , Matthew Wilcox , David Rientjes Subject: Re: [PATCH v4 1/3] mm/free_pcppages_bulk: update pcp->count inside Message-ID: <20180301134512.GI15057@dhcp22.suse.cz> References: <20180301062845.26038-1-aaron.lu@intel.com> <20180301062845.26038-2-aaron.lu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180301062845.26038-2-aaron.lu@intel.com> User-Agent: Mutt/1.9.3 (2018-01-21) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 01-03-18 14:28:43, Aaron Lu wrote: > Matthew Wilcox found that all callers of free_pcppages_bulk() currently > update pcp->count immediately after so it's natural to do it inside > free_pcppages_bulk(). > > No functionality or performance change is expected from this patch. > > Suggested-by: Matthew Wilcox > Signed-off-by: Aaron Lu Makes a lot of sense to me. Acked-by: Michal Hocko > --- > mm/page_alloc.c | 10 +++------- > 1 file changed, 3 insertions(+), 7 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index cb416723538f..faa33eac1635 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1148,6 +1148,7 @@ static void free_pcppages_bulk(struct zone *zone, int count, > page = list_last_entry(list, struct page, lru); > /* must delete as __free_one_page list manipulates */ > list_del(&page->lru); > + pcp->count--; > > mt = get_pcppage_migratetype(page); > /* MIGRATE_ISOLATE page should not go to pcplists */ > @@ -2416,10 +2417,8 @@ void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp) > local_irq_save(flags); > batch = READ_ONCE(pcp->batch); > to_drain = min(pcp->count, batch); > - if (to_drain > 0) { > + if (to_drain > 0) > free_pcppages_bulk(zone, to_drain, pcp); > - pcp->count -= to_drain; > - } > local_irq_restore(flags); > } > #endif > @@ -2441,10 +2440,8 @@ static void drain_pages_zone(unsigned int cpu, struct zone *zone) > pset = per_cpu_ptr(zone->pageset, cpu); > > pcp = &pset->pcp; > - if (pcp->count) { > + if (pcp->count) > free_pcppages_bulk(zone, pcp->count, pcp); > - pcp->count = 0; > - } > local_irq_restore(flags); > } > > @@ -2668,7 +2665,6 @@ static void free_unref_page_commit(struct page *page, unsigned long pfn) > if (pcp->count >= pcp->high) { > unsigned long batch = READ_ONCE(pcp->batch); > free_pcppages_bulk(zone, batch, pcp); > - pcp->count -= batch; > } > } > > -- > 2.14.3 > -- Michal Hocko SUSE Labs From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f198.google.com (mail-wr0-f198.google.com [209.85.128.198]) by kanga.kvack.org (Postfix) with ESMTP id 6DC8B6B0005 for ; Thu, 1 Mar 2018 08:45:15 -0500 (EST) Received: by mail-wr0-f198.google.com with SMTP id r15so4113908wrr.16 for ; Thu, 01 Mar 2018 05:45:15 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id o13si2606262wmf.89.2018.03.01.05.45.13 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 01 Mar 2018 05:45:13 -0800 (PST) Date: Thu, 1 Mar 2018 14:45:12 +0100 From: Michal Hocko Subject: Re: [PATCH v4 1/3] mm/free_pcppages_bulk: update pcp->count inside Message-ID: <20180301134512.GI15057@dhcp22.suse.cz> References: <20180301062845.26038-1-aaron.lu@intel.com> <20180301062845.26038-2-aaron.lu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180301062845.26038-2-aaron.lu@intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Aaron Lu Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Huang Ying , Dave Hansen , Kemi Wang , Tim Chen , Andi Kleen , Vlastimil Babka , Mel Gorman , Matthew Wilcox , David Rientjes On Thu 01-03-18 14:28:43, Aaron Lu wrote: > Matthew Wilcox found that all callers of free_pcppages_bulk() currently > update pcp->count immediately after so it's natural to do it inside > free_pcppages_bulk(). > > No functionality or performance change is expected from this patch. > > Suggested-by: Matthew Wilcox > Signed-off-by: Aaron Lu Makes a lot of sense to me. Acked-by: Michal Hocko > --- > mm/page_alloc.c | 10 +++------- > 1 file changed, 3 insertions(+), 7 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index cb416723538f..faa33eac1635 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1148,6 +1148,7 @@ static void free_pcppages_bulk(struct zone *zone, int count, > page = list_last_entry(list, struct page, lru); > /* must delete as __free_one_page list manipulates */ > list_del(&page->lru); > + pcp->count--; > > mt = get_pcppage_migratetype(page); > /* MIGRATE_ISOLATE page should not go to pcplists */ > @@ -2416,10 +2417,8 @@ void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp) > local_irq_save(flags); > batch = READ_ONCE(pcp->batch); > to_drain = min(pcp->count, batch); > - if (to_drain > 0) { > + if (to_drain > 0) > free_pcppages_bulk(zone, to_drain, pcp); > - pcp->count -= to_drain; > - } > local_irq_restore(flags); > } > #endif > @@ -2441,10 +2440,8 @@ static void drain_pages_zone(unsigned int cpu, struct zone *zone) > pset = per_cpu_ptr(zone->pageset, cpu); > > pcp = &pset->pcp; > - if (pcp->count) { > + if (pcp->count) > free_pcppages_bulk(zone, pcp->count, pcp); > - pcp->count = 0; > - } > local_irq_restore(flags); > } > > @@ -2668,7 +2665,6 @@ static void free_unref_page_commit(struct page *page, unsigned long pfn) > if (pcp->count >= pcp->high) { > unsigned long batch = READ_ONCE(pcp->batch); > free_pcppages_bulk(zone, batch, pcp); > - pcp->count -= batch; > } > } > > -- > 2.14.3 > -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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