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=-12.7 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 9CBA2C04EBE for ; Thu, 8 Oct 2020 11:42:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 644F521527 for ; Thu, 8 Oct 2020 11:42:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729891AbgJHLmM (ORCPT ); Thu, 8 Oct 2020 07:42:12 -0400 Received: from mx2.suse.de ([195.135.220.15]:40544 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729877AbgJHLmK (ORCPT ); Thu, 8 Oct 2020 07:42:10 -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 BD377B28E; Thu, 8 Oct 2020 11:42:07 +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 v2 5/7] mm, page_alloc: cache pageset high and batch in struct zone Date: Thu, 8 Oct 2020 13:41:59 +0200 Message-Id: <20201008114201.18824-6-vbabka@suse.cz> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201008114201.18824-1-vbabka@suse.cz> References: <20201008114201.18824-1-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 | 17 +++++++++++++++-- 2 files changed, 21 insertions(+), 2 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index fb3bf696c05e..c63863794afc 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 f33c36312eb5..5b98dd5ab006 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5900,6 +5900,9 @@ 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); +/* These effectively disable the pcplists in the boot pageset completely */ +#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); @@ -6289,8 +6292,8 @@ 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; } /* @@ -6314,6 +6317,14 @@ 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); @@ -6374,6 +6385,8 @@ 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