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=-9.0 required=3.0 tests=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 BE8C1C28CC0 for ; Thu, 30 May 2019 16:10:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9E37625D5F for ; Thu, 30 May 2019 16:10:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727692AbfE3QKh (ORCPT ); Thu, 30 May 2019 12:10:37 -0400 Received: from foss.arm.com ([217.140.101.70]:39198 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726015AbfE3QKh (ORCPT ); Thu, 30 May 2019 12:10:37 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B902B341; Thu, 30 May 2019 09:10:36 -0700 (PDT) Received: from eglon.cambridge.arm.com (eglon.cambridge.arm.com [10.1.196.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 849913F5AF; Thu, 30 May 2019 09:10:35 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , "Rafael J . Wysocki" , Fenghua Yu , Reinette Chatre , james.morse@arm.com Subject: [PATCH] drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT Date: Thu, 30 May 2019 17:10:24 +0100 Message-Id: <20190530161024.85637-1-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The cacheinfo structures are alloced/freed by cpu online/offline callbacks. Originally these were only used by sysfs to expose the cache topology to user space. Without any in-kernel dependencies CPUHP_AP_ONLINE_DYN was an appropriate choice. resctrl has started using these structures to identify CPUs that share a cache. It updates its 'domain' structures from cpu online/offline callbacks. These depend on the cacheinfo structures (resctrl_online_cpu()->domain_add_cpu()->get_cache_id()-> get_cpu_cacheinfo()). These also run as CPUHP_AP_ONLINE_DYN. Now that there is an in-kernel dependency, move the cacheinfo work earlier so we know its done before resctrl's CPUHP_AP_ONLINE_DYN work runs. Cc: Fenghua Yu Cc: Reinette Chatre Signed-off-by: James Morse --- I haven't seen any problems because of this. If someone thinks it should go to stable: Cc: #4.10.x The particular patch that added RDT is: Fixes: 2264d9c74dda1 ("x86/intel_rdt: Build structures for each resource based on cache topology") But as this touches a different set of files, I'm not sure how appropriate a fixes tag is. drivers/base/cacheinfo.c | 3 ++- include/linux/cpuhotplug.h | 1 + 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c index a7359535caf5..b444f89a2041 100644 --- a/drivers/base/cacheinfo.c +++ b/drivers/base/cacheinfo.c @@ -655,7 +655,8 @@ static int cacheinfo_cpu_pre_down(unsigned int cpu) static int __init cacheinfo_sysfs_init(void) { - return cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "base/cacheinfo:online", + return cpuhp_setup_state(CPUHP_AP_BASE_CACHEINFO_ONLINE, + "base/cacheinfo:online", cacheinfo_cpu_online, cacheinfo_cpu_pre_down); } device_initcall(cacheinfo_sysfs_init); diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 6a381594608c..50c893f03c21 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -175,6 +175,7 @@ enum cpuhp_state { CPUHP_AP_WATCHDOG_ONLINE, CPUHP_AP_WORKQUEUE_ONLINE, CPUHP_AP_RCUTREE_ONLINE, + CPUHP_AP_BASE_CACHEINFO_ONLINE, CPUHP_AP_ONLINE_DYN, CPUHP_AP_ONLINE_DYN_END = CPUHP_AP_ONLINE_DYN + 30, CPUHP_AP_X86_HPET_ONLINE, -- 2.20.1