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=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 2318DC4363D for ; Tue, 22 Sep 2020 14:37:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E19E42395C for ; Tue, 22 Sep 2020 14:37:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726784AbgIVOhp (ORCPT ); Tue, 22 Sep 2020 10:37:45 -0400 Received: from mx2.suse.de ([195.135.220.15]:46492 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726566AbgIVOhX (ORCPT ); Tue, 22 Sep 2020 10:37:23 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 3DD02B120; Tue, 22 Sep 2020 14:37:57 +0000 (UTC) From: Vlastimil Babka To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Michal Hocko , Pavel Tatashin , David Hildenbrand , Oscar Salvador , Joonsoo Kim , Vlastimil Babka Subject: [PATCH 6/9] mm, page_alloc: cache pageset high and batch in struct zone Date: Tue, 22 Sep 2020 16:37:09 +0200 Message-Id: <20200922143712.12048-7-vbabka@suse.cz> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200922143712.12048-1-vbabka@suse.cz> References: <20200922143712.12048-1-vbabka@suse.cz> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org All per-cpu pagesets for a zone use the same high and batch values, that are duplicated there just for performance (locality) reasons. This patch adds the same variables also to struct zone as a shared copy. This will be useful later for making possible to disable pcplists temporarily by setting high value to 0, while remembering the values for restoring them later. But we can also immediately benefit from not updating pagesets of all possible cpus in case the newly recalculated values (after sysctl change or memory online/offline) are actually unchanged from the previous ones. Signed-off-by: Vlastimil Babka --- include/linux/mmzone.h | 6 ++++++ mm/page_alloc.c | 16 ++++++++++++++-- 2 files changed, 20 insertions(+), 2 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 90721f3156bc..7ad3f14dbe88 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -470,6 +470,12 @@ struct zone { #endif struct pglist_data *zone_pgdat; struct per_cpu_pageset __percpu *pageset; + /* + * the high and batch values are copied to individual pagesets for + * faster access + */ + int pageset_high; + int pageset_batch; #ifndef CONFIG_SPARSEMEM /* diff --git a/mm/page_alloc.c b/mm/page_alloc.c index de3b48bda45c..901907799bdc 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5824,6 +5824,8 @@ static void build_zonelists(pg_data_t *pgdat) * Other parts of the kernel may not check if the zone is available. */ static void pageset_init(struct per_cpu_pageset *p); +#define BOOT_PAGESET_HIGH 0 +#define BOOT_PAGESET_BATCH 1 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset); static DEFINE_PER_CPU(struct per_cpu_nodestat, boot_nodestats); @@ -6213,8 +6215,8 @@ static void pageset_init(struct per_cpu_pageset *p) * need to be as careful as pageset_update() as nobody can access the * pageset yet. */ - pcp->high = 0; - pcp->batch = 1; + pcp->high = BOOT_PAGESET_HIGH; + pcp->batch = BOOT_PAGESET_BATCH; } /* @@ -6238,6 +6240,14 @@ static void zone_set_pageset_high_and_batch(struct zone *zone) new_batch = max(1UL, 1 * new_batch); } + if (zone->pageset_high != new_high || + zone->pageset_batch != new_batch) { + zone->pageset_high = new_high; + zone->pageset_batch = new_batch; + } else { + return; + } + for_each_possible_cpu(cpu) { p = per_cpu_ptr(zone->pageset, cpu); pageset_update(&p->pcp, new_high, new_batch); @@ -6300,6 +6310,8 @@ static __meminit void zone_pcp_init(struct zone *zone) * offset of a (static) per cpu variable into the per cpu area. */ zone->pageset = &boot_pageset; + zone->pageset_high = BOOT_PAGESET_HIGH; + zone->pageset_batch = BOOT_PAGESET_BATCH; if (populated_zone(zone)) printk(KERN_DEBUG " %s zone: %lu pages, LIFO batch:%u\n", -- 2.28.0