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 EDF68C433F5 for ; Tue, 12 Apr 2022 07:33:37 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6D38F6B0074; Tue, 12 Apr 2022 03:33:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 683BB6B007B; Tue, 12 Apr 2022 03:33:37 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 54AE16B007D; Tue, 12 Apr 2022 03:33:37 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.25]) by kanga.kvack.org (Postfix) with ESMTP id 3FF5C6B0074 for ; Tue, 12 Apr 2022 03:33:37 -0400 (EDT) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 072A620DD1 for ; Tue, 12 Apr 2022 07:33:37 +0000 (UTC) X-FDA: 79347412074.04.D42089F Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by imf13.hostedemail.com (Postfix) with ESMTP id 3100F20002 for ; Tue, 12 Apr 2022 07:33:36 +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 F12EE21605; Tue, 12 Apr 2022 07:33:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1649748814; 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=8WooxKKBixM8mITlHzWMPiAPHChjP6eAz1xgWLIa7aU=; b=cS+dkFmZoOYZxhop8IUUcOHCDFlsu25j6Ceg/sBN1Rcq1OeSjCxj1HfOiz51kTlZK+7pLf HdJLQygCnizNePDV+O3jHJxdKLpNubDCzQ3CSbyB60xG+Di3lF+h9cEHATsIgLuPci0PCx GMrW+x79XmfUqzKFdqVYLgfPp+anUrI= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1649748814; 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=8WooxKKBixM8mITlHzWMPiAPHChjP6eAz1xgWLIa7aU=; b=8ncHku3HJFeAC0dDupXBtfwBKQjAQmg12ptZPiX0dqnxPda1uEWygJd0LcXey8LgRFt5Rx UUhm8BcnmCIndiCA== 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 D7CFD13A99; Tue, 12 Apr 2022 07:33:34 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id Yv8CNE4rVWIHewAAMHmgww (envelope-from ); Tue, 12 Apr 2022 07:33:34 +0000 Message-ID: Date: Tue, 12 Apr 2022 09:33:34 +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 v3] 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, David Hildenbrand , Oscar Salvador References: <20220412001319.7462-1-richard.weiyang@gmail.com> From: Vlastimil Babka In-Reply-To: <20220412001319.7462-1-richard.weiyang@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=cS+dkFmZ; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=8ncHku3H; spf=pass (imf13.hostedemail.com: domain of vbabka@suse.cz designates 195.135.220.28 as permitted sender) smtp.mailfrom=vbabka@suse.cz; dmarc=none X-Stat-Signature: ze9qhz4shd4wgjfeggsya4rx6jcis1pa X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 3100F20002 X-HE-Tag: 1649748816-189064 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 4/12/22 02:13, 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. Since we just increase a constance of 1 to node > penalty, it is not necessary to multiply MAX_NODE_LOAD for preference. > > [vbabka@suse.cz: suggests to remove MAX_NODE_LOAD] > > Signed-off-by: Wei Yang > CC: Vlastimil Babka > CC: David Hildenbrand > CC: Oscar Salvador Acked-by: Vlastimil Babka > v3: merge into a single patch > v2: adjust constant penalty to 1 > --- > mm/page_alloc.c | 9 +++------ > 1 file changed, 3 insertions(+), 6 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 5d71b8dcb5f4..0334c06a0a47 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -6170,7 +6170,6 @@ int numa_zonelist_order_handler(struct ctl_table *table, int write, > } > > > -#define MAX_NODE_LOAD (nr_online_nodes) > static int node_load[MAX_NUMNODES]; > > /** > @@ -6217,7 +6216,7 @@ int find_next_best_node(int node, nodemask_t *used_node_mask) > val += PENALTY_FOR_NODE_WITH_CPUS; > > /* Slight preference for less loaded node */ > - val *= (MAX_NODE_LOAD*MAX_NUMNODES); > + val *= MAX_NUMNODES; > val += node_load[n]; > > if (val < min_val) { > @@ -6283,13 +6282,12 @@ 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)); > @@ -6301,11 +6299,10 @@ 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] += 1; > > node_order[nr_nodes++] = node; > prev_node = node; > - load--; > } > > build_zonelists_in_node_order(pgdat, node_order, nr_nodes);