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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 9F2CFC433F5 for ; Thu, 16 Sep 2021 17:11:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8895E60EE9 for ; Thu, 16 Sep 2021 17:11:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350786AbhIPRMa (ORCPT ); Thu, 16 Sep 2021 13:12:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:34012 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349172AbhIPRDt (ORCPT ); Thu, 16 Sep 2021 13:03:49 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0D20861268; Thu, 16 Sep 2021 16:34:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1631810068; bh=jZTT1EGsWwgZLxMN9FaJxmNT8OaXS7ODP6cR+l/zhes=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=e6UGfUnVpnz8DWMYQQnsviOPDFyKPp7X02s2m0mQ6trBCitJ1rRSO0JZiebiR3aGL dpqCw9CrMM9Gv5aSu0rrW/SPfExxMzzHD6akniwe8gd4qJzdssGUrgGOJVnjp0jQx+ ilMD4FNQhDlhs3BeVvY7X/LdUSqIHPr8CZH5izrA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sven Schnelle , Heiko Carstens Subject: [PATCH 5.13 356/380] s390/topology: fix topology information when calling cpu hotplug notifiers Date: Thu, 16 Sep 2021 18:01:53 +0200 Message-Id: <20210916155816.167690739@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210916155803.966362085@linuxfoundation.org> References: <20210916155803.966362085@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sven Schnelle commit a052096bdd6809eeab809202726634d1ac975aa1 upstream. The cpu hotplug notifiers are called without updating the core/thread masks when a new CPU is added. This causes problems with code setting up data structures in a cpu hotplug notifier, and relying on that later in normal code. This caused a crash in the new core scheduling code (SCHED_CORE), where rq->core was set up in a notifier depending on cpu masks. To fix this, add a cpu_setup_mask which is used in update_cpu_masks() instead of the cpu_online_mask to determine whether the cpu masks should be set for a certain cpu. Also move update_cpu_masks() to update the masks before calling notify_cpu_starting() so that the notifiers are seeing the updated masks. Signed-off-by: Sven Schnelle Cc: [hca@linux.ibm.com: get rid of cpu_online_mask handling] Signed-off-by: Heiko Carstens Signed-off-by: Greg Kroah-Hartman --- arch/s390/include/asm/smp.h | 1 + arch/s390/kernel/smp.c | 9 +++++++-- arch/s390/kernel/topology.c | 13 +++++++------ 3 files changed, 15 insertions(+), 8 deletions(-) --- a/arch/s390/include/asm/smp.h +++ b/arch/s390/include/asm/smp.h @@ -18,6 +18,7 @@ extern struct mutex smp_cpu_state_mutex; extern unsigned int smp_cpu_mt_shift; extern unsigned int smp_cpu_mtid; extern __vector128 __initdata boot_cpu_vector_save_area[__NUM_VXRS]; +extern cpumask_t cpu_setup_mask; extern int __cpu_up(unsigned int cpu, struct task_struct *tidle); --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -96,6 +96,7 @@ __vector128 __initdata boot_cpu_vector_s #endif static unsigned int smp_max_threads __initdata = -1U; +cpumask_t cpu_setup_mask; static int __init early_nosmt(char *s) { @@ -883,13 +884,14 @@ static void smp_init_secondary(void) vtime_init(); vdso_getcpu_init(); pfault_init(); + cpumask_set_cpu(cpu, &cpu_setup_mask); + update_cpu_masks(); notify_cpu_starting(cpu); if (topology_cpu_dedicated(cpu)) set_cpu_flag(CIF_DEDICATED_CPU); else clear_cpu_flag(CIF_DEDICATED_CPU); set_cpu_online(cpu, true); - update_cpu_masks(); inc_irq_stat(CPU_RST); local_irq_enable(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); @@ -945,10 +947,13 @@ early_param("possible_cpus", _setup_poss int __cpu_disable(void) { unsigned long cregs[16]; + int cpu; /* Handle possible pending IPIs */ smp_handle_ext_call(); - set_cpu_online(smp_processor_id(), false); + cpu = smp_processor_id(); + set_cpu_online(cpu, false); + cpumask_clear_cpu(cpu, &cpu_setup_mask); update_cpu_masks(); /* Disable pseudo page faults on this cpu. */ pfault_fini(); --- a/arch/s390/kernel/topology.c +++ b/arch/s390/kernel/topology.c @@ -67,7 +67,7 @@ static void cpu_group_map(cpumask_t *dst static cpumask_t mask; cpumask_clear(&mask); - if (!cpu_online(cpu)) + if (!cpumask_test_cpu(cpu, &cpu_setup_mask)) goto out; cpumask_set_cpu(cpu, &mask); switch (topology_mode) { @@ -88,7 +88,7 @@ static void cpu_group_map(cpumask_t *dst case TOPOLOGY_MODE_SINGLE: break; } - cpumask_and(&mask, &mask, cpu_online_mask); + cpumask_and(&mask, &mask, &cpu_setup_mask); out: cpumask_copy(dst, &mask); } @@ -99,16 +99,16 @@ static void cpu_thread_map(cpumask_t *ds int i; cpumask_clear(&mask); - if (!cpu_online(cpu)) + if (!cpumask_test_cpu(cpu, &cpu_setup_mask)) goto out; cpumask_set_cpu(cpu, &mask); if (topology_mode != TOPOLOGY_MODE_HW) goto out; cpu -= cpu % (smp_cpu_mtid + 1); - for (i = 0; i <= smp_cpu_mtid; i++) - if (cpu_present(cpu + i)) + for (i = 0; i <= smp_cpu_mtid; i++) { + if (cpumask_test_cpu(cpu + i, &cpu_setup_mask)) cpumask_set_cpu(cpu + i, &mask); - cpumask_and(&mask, &mask, cpu_online_mask); + } out: cpumask_copy(dst, &mask); } @@ -569,6 +569,7 @@ void __init topology_init_early(void) alloc_masks(info, &book_info, 2); alloc_masks(info, &drawer_info, 3); out: + cpumask_set_cpu(0, &cpu_setup_mask); __arch_update_cpu_topology(); __arch_update_dedicated_flag(NULL); }