From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f197.google.com (mail-pf0-f197.google.com [209.85.192.197]) by kanga.kvack.org (Postfix) with ESMTP id 77DDD6B0253 for ; Tue, 9 Aug 2016 08:30:24 -0400 (EDT) Received: by mail-pf0-f197.google.com with SMTP id w128so21779341pfd.3 for ; Tue, 09 Aug 2016 05:30:24 -0700 (PDT) Received: from szxga03-in.huawei.com (szxga03-in.huawei.com. [119.145.14.66]) by mx.google.com with ESMTPS id tf1si42567053pab.230.2016.08.09.05.30.22 for (version=TLS1 cipher=AES128-SHA bits=128/128); Tue, 09 Aug 2016 05:30:23 -0700 (PDT) Message-ID: <57A9CB06.5010201@huawei.com> Date: Tue, 9 Aug 2016 20:22:30 +0800 From: zhong jiang MIME-Version: 1.0 Subject: Re: [PATCH] mm: optimize find_zone_movable_pfns_for_nodes to avoid unnecessary loop. References: <1470405847-53322-1-git-send-email-zhongjiang@huawei.com> In-Reply-To: <1470405847-53322-1-git-send-email-zhongjiang@huawei.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Michal Hocko , mgorman@techsingularity.net, Vlastimil Babka , Minchan Kim , Joonsoo Kim On 2016/8/5 22:04, zhongjiang wrote: > From: zhong jiang > > when required_kernelcore decrease to zero, we should exit the loop in time. > because It will waste time to scan the remainder node. > > Signed-off-by: zhong jiang > --- > mm/page_alloc.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index ea759b9..be7df17 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -6093,7 +6093,7 @@ static unsigned long __init early_calculate_totalpages(void) > unsigned long pages = end_pfn - start_pfn; > > totalpages += pages; > - if (pages) > + if (!node_isset(nid, node_states[N_MEMORY]) && pages) > node_set_state(nid, N_MEMORY); > } > return totalpages; > @@ -6115,6 +6115,7 @@ static void __init find_zone_movable_pfns_for_nodes(void) > unsigned long totalpages = early_calculate_totalpages(); > int usable_nodes = nodes_weight(node_states[N_MEMORY]); > struct memblock_region *r; > + bool avoid_loop = false; > > /* Need to find movable_zone earlier when movable_node is specified. */ > find_usable_zone_for_movable(); > @@ -6275,6 +6276,8 @@ restart: > required_kernelcore -= min(required_kernelcore, > size_pages); > kernelcore_remaining -= size_pages; > + if (!required_kernelcore && avoid_loop) > + goto out2; > if (!kernelcore_remaining) > break; > } > @@ -6287,9 +6290,10 @@ restart: > * satisfied > */ > usable_nodes--; > - if (usable_nodes && required_kernelcore > usable_nodes) > + if (usable_nodes && required_kernelcore > usable_nodes) { > + avoid_loop = true; > goto restart; > - > + } > out2: > /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */ > for (nid = 0; nid < MAX_NUMNODES; nid++) Any one have any objection about above patch ? please let me know. -- 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