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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 4FBE9C43460 for ; Wed, 7 Apr 2021 20:26:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 26607611EE for ; Wed, 7 Apr 2021 20:26:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356303AbhDGU0v (ORCPT ); Wed, 7 Apr 2021 16:26:51 -0400 Received: from outbound-smtp31.blacknight.com ([81.17.249.62]:45903 "EHLO outbound-smtp31.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356143AbhDGUZ7 (ORCPT ); Wed, 7 Apr 2021 16:25:59 -0400 Received: from mail.blacknight.com (pemlinmail01.blacknight.ie [81.17.254.10]) by outbound-smtp31.blacknight.com (Postfix) with ESMTPS id CB767C0D7A for ; Wed, 7 Apr 2021 21:25:46 +0100 (IST) Received: (qmail 16972 invoked from network); 7 Apr 2021 20:25:46 -0000 Received: from unknown (HELO stampy.112glenside.lan) (mgorman@techsingularity.net@[84.203.22.4]) by 81.17.254.9 with ESMTPA; 7 Apr 2021 20:25:46 -0000 From: Mel Gorman To: Linux-MM , Linux-RT-Users Cc: LKML , Chuck Lever , Jesper Dangaard Brouer , Matthew Wilcox , Thomas Gleixner , Peter Zijlstra , Ingo Molnar , Michal Hocko , Oscar Salvador , Mel Gorman Subject: [PATCH 07/11] mm/page_alloc: Reduce duration that IRQs are disabled for VM counters Date: Wed, 7 Apr 2021 21:24:19 +0100 Message-Id: <20210407202423.16022-8-mgorman@techsingularity.net> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210407202423.16022-1-mgorman@techsingularity.net> References: <20210407202423.16022-1-mgorman@techsingularity.net> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org IRQs are left disabled for the zone and node VM event counters. This is unnecessary as the affected counters are allowed to race for preemmption and IRQs. This patch reduces the scope of IRQs being disabled via local_[lock|unlock]_irq on !PREEMPT_RT kernels. One __mod_zone_freepage_state is still called with IRQs disabled. While this could be moved out, it's not free on all architectures as some require IRQs to be disabled for mod_zone_page_state on !PREEMPT_RTkernels. Signed-off-by: Mel Gorman --- mm/page_alloc.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index defb0e436fac..bd75102ef1e1 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3474,11 +3474,11 @@ static struct page *rmqueue_pcplist(struct zone *preferred_zone, pcp = this_cpu_ptr(zone->per_cpu_pageset); list = &pcp->lists[migratetype]; page = __rmqueue_pcplist(zone, migratetype, alloc_flags, pcp, list); + local_unlock_irqrestore(&pagesets.lock, flags); if (page) { __count_zid_vm_events(PGALLOC, page_zonenum(page), 1); zone_statistics(preferred_zone, zone, 1); } - local_unlock_irqrestore(&pagesets.lock, flags); return page; } @@ -3530,15 +3530,15 @@ struct page *rmqueue(struct zone *preferred_zone, if (!page) page = __rmqueue(zone, order, migratetype, alloc_flags); } while (page && check_new_pages(page, order)); - spin_unlock(&zone->lock); if (!page) goto failed; + __mod_zone_freepage_state(zone, -(1 << order), get_pcppage_migratetype(page)); + spin_unlock_irqrestore(&zone->lock, flags); __count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order); zone_statistics(preferred_zone, zone, 1); - local_irq_restore(flags); out: /* Separate test+clear to avoid unnecessary atomics */ @@ -3551,7 +3551,7 @@ struct page *rmqueue(struct zone *preferred_zone, return page; failed: - local_irq_restore(flags); + spin_unlock_irqrestore(&zone->lock, flags); return NULL; } @@ -5103,11 +5103,11 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid, nr_populated++; } + local_unlock_irqrestore(&pagesets.lock, flags); + __count_zid_vm_events(PGALLOC, zone_idx(zone), nr_account); zone_statistics(ac.preferred_zoneref->zone, zone, nr_account); - local_unlock_irqrestore(&pagesets.lock, flags); - return nr_populated; failed_irq: -- 2.26.2