From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7BA26C433F5 for ; Tue, 5 Apr 2022 17:11:36 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B5A6F6B0072; Tue, 5 Apr 2022 13:11:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B09756B0073; Tue, 5 Apr 2022 13:11:25 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9AB496B0074; Tue, 5 Apr 2022 13:11:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0129.hostedemail.com [216.40.44.129]) by kanga.kvack.org (Postfix) with ESMTP id 87BF16B0072 for ; Tue, 5 Apr 2022 13:11:25 -0400 (EDT) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 3777A183BA07A for ; Tue, 5 Apr 2022 17:11:15 +0000 (UTC) X-FDA: 79323466110.18.2488CDA Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by imf11.hostedemail.com (Postfix) with ESMTP id 54F5B40021 for ; Tue, 5 Apr 2022 17:11:14 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id BEE1D210FD; Tue, 5 Apr 2022 17:11:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1649178672; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=qXZaguQgzHHMZTiLw5gbfQ9kh4XyH0tzaiUaS6uMhFw=; b=P1Niw4x7r4HvoVhVpJmYRniTerVWGNQa6wUn7Ui1YBWr3GPrTv/DDxtfkvC2CYjhu4hPwt vRo+RBTSUTI2wSww9e+aNNtAJDjdZK/C+6YaX98Vj07u/ft/IbH09AI6kOOthu2Z+1MU0T FXIgvSyFmpbK4wYkorchJoof5s0UgxM= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1649178672; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=qXZaguQgzHHMZTiLw5gbfQ9kh4XyH0tzaiUaS6uMhFw=; b=1mPAQK/8Tc5VWkJTuIOTeqpAAr7YKV2IrbOKQ8iV5kuhxX8JwS1ELK4F58khGigxtSLgop AGReuck+EL/60AAQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id AB5D113A04; Tue, 5 Apr 2022 17:11:12 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id AY4eKTB4TGK7HwAAMHmgww (envelope-from ); Tue, 05 Apr 2022 17:11:12 +0000 Message-ID: Date: Tue, 5 Apr 2022 19:11:12 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [PATCH 1/2] mm/page_alloc: add same penalty is enough to get round-robin order Content-Language: en-US To: Wei Yang , akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20220123013537.20491-1-richard.weiyang@gmail.com> From: Vlastimil Babka In-Reply-To: <20220123013537.20491-1-richard.weiyang@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 54F5B40021 X-Stat-Signature: dz8pztc8hts7ujmxtsctmabg4a5sywmn Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=P1Niw4x7; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b="1mPAQK/8"; dmarc=none; spf=pass (imf11.hostedemail.com: domain of vbabka@suse.cz designates 195.135.220.28 as permitted sender) smtp.mailfrom=vbabka@suse.cz X-Rspam-User: X-HE-Tag: 1649178674-919714 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 1/23/22 02:35, Wei Yang wrote: > To make node order in round-robin in the same distance group, we add a > penalty to the first node we got in each round. > > To get a round-robin order in the same distance group, we don't need to > decrease the penalty since: > > * find_next_best_node() always iterates node in the same order > * distance matters more then penalty in find_next_best_node() > * in nodes with the same distance, the first one would be picked up > > So it is fine to increase same penalty when we get the first node in the > same distance group. With that logic I'm not even sure if we need nr_online_nodes as penalty or it could be just 1. Would you know? > > Signed-off-by: Wei Yang > --- > mm/page_alloc.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index c5952749ad40..f27afd517652 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -6245,13 +6245,12 @@ static void build_thisnode_zonelists(pg_data_t *pgdat) > static void build_zonelists(pg_data_t *pgdat) > { > static int node_order[MAX_NUMNODES]; > - int node, load, nr_nodes = 0; > + int node, nr_nodes = 0; > nodemask_t used_mask = NODE_MASK_NONE; > int local_node, prev_node; > > /* NUMA-aware ordering of nodes */ > local_node = pgdat->node_id; > - load = nr_online_nodes; > prev_node = local_node; > > memset(node_order, 0, sizeof(node_order)); > @@ -6263,11 +6262,10 @@ static void build_zonelists(pg_data_t *pgdat) > */ > if (node_distance(local_node, node) != > node_distance(local_node, prev_node)) > - node_load[node] += load; > + node_load[node] += nr_online_nodes; > > node_order[nr_nodes++] = node; > prev_node = node; > - load--; > } > > build_zonelists_in_node_order(pgdat, node_order, nr_nodes);