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 X-Spam-Level: X-Spam-Status: No, score=-11.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 20195C4363A for ; Mon, 5 Oct 2020 12:59:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D2C732078D for ; Mon, 5 Oct 2020 12:59:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="Mr8NVk3j" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726057AbgJEM7t (ORCPT ); Mon, 5 Oct 2020 08:59:49 -0400 Received: from mx2.suse.de ([195.135.220.15]:33064 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725891AbgJEM7t (ORCPT ); Mon, 5 Oct 2020 08:59:49 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1601902788; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=kCM0oof2PQlpqDAFDYbRfe2VVJ0jwjtnBd72MEgWLrY=; b=Mr8NVk3jK92CRd9X4z4PT6ZjAJ2N0fJwCULzy9k5qDzgjZdI4XBP8k14mPGGj3P8FT/hrF QBKQQ6RsGMKWxQOv2wtGxc0iSLRUMwbjeOdGpem8CsktlGqRsM3t/EsM32AE2jKtsjjbMm Ev7t1JdtFcN6P6D76LtjNPfMqpZTZkU= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id DB771AC4C; Mon, 5 Oct 2020 12:59:47 +0000 (UTC) Date: Mon, 5 Oct 2020 14:59:46 +0200 From: Michal Hocko To: Vlastimil Babka Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Pavel Tatashin , David Hildenbrand , Oscar Salvador , Joonsoo Kim Subject: Re: [PATCH 3/9] mm, page_alloc: remove setup_pageset() Message-ID: <20201005125946.GY4555@dhcp22.suse.cz> References: <20200922143712.12048-1-vbabka@suse.cz> <20200922143712.12048-4-vbabka@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200922143712.12048-4-vbabka@suse.cz> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 22-09-20 16:37:06, Vlastimil Babka wrote: > We initialize boot-time pagesets with setup_pageset(), which sets high and > batch values that effectively disable pcplists. > > We can remove this wrapper if we just set these values for all pagesets in > pageset_init(). Non-boot pagesets then subsequently update them to the proper > values. > > No functional change. > > Signed-off-by: Vlastimil Babka > --- > mm/page_alloc.c | 17 ++++++++++------- > 1 file changed, 10 insertions(+), 7 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 26069c8d1b19..76c2b4578723 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -5823,7 +5823,7 @@ static void build_zonelists(pg_data_t *pgdat) > * not check if the processor is online before following the pageset pointer. > * Other parts of the kernel may not check if the zone is available. > */ > -static void setup_pageset(struct per_cpu_pageset *p); > +static void pageset_init(struct per_cpu_pageset *p); > static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset); > static DEFINE_PER_CPU(struct per_cpu_nodestat, boot_nodestats); > > @@ -5891,7 +5891,7 @@ build_all_zonelists_init(void) > * (a chicken-egg dilemma). > */ > for_each_possible_cpu(cpu) > - setup_pageset(&per_cpu(boot_pageset, cpu)); > + pageset_init(&per_cpu(boot_pageset, cpu)); > > mminit_verify_zonelist(); > cpuset_init_current_mems_allowed(); > @@ -6210,12 +6210,15 @@ static void pageset_init(struct per_cpu_pageset *p) > pcp = &p->pcp; > for (migratetype = 0; migratetype < MIGRATE_PCPTYPES; migratetype++) > INIT_LIST_HEAD(&pcp->lists[migratetype]); > -} > > -static void setup_pageset(struct per_cpu_pageset *p) > -{ > - pageset_init(p); > - pageset_update(&p->pcp, 0, 1); > + /* > + * Set batch and high values safe for a boot pageset. A true percpu > + * pageset's initialization will update them subsequently. Here we don't > + * need to be as careful as pageset_update() as nobody can access the > + * pageset yet. Isn't this slightly misleading? pageset_init is called from setup_zone_pageset which is called from the memory hotplug as well. Isn't this more about early zone initialization rather than boot pagesets? Or am I misreading the patch? > + */ > + pcp->high = 0; > + pcp->batch = 1; > } > > /* > -- > 2.28.0 -- Michal Hocko SUSE Labs