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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 557BCC433F5 for ; Thu, 11 Nov 2021 12:39:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F35126135E for ; Thu, 11 Nov 2021 12:39:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232908AbhKKMmR (ORCPT ); Thu, 11 Nov 2021 07:42:17 -0500 Received: from office.oderland.com ([91.201.60.5]:39752 "EHLO office.oderland.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229946AbhKKMmQ (ORCPT ); Thu, 11 Nov 2021 07:42:16 -0500 Received: from [193.180.18.161] (port=36378 helo=[10.137.0.14]) by office.oderland.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94.2) (envelope-from ) id 1ml9MS-00754Y-HK; Thu, 11 Nov 2021 13:39:24 +0100 Message-ID: <132343df-df01-6ab6-bdaf-cd1605028bfc@oderland.se> Date: Thu, 11 Nov 2021 13:39:20 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:93.0) Gecko/20100101 Thunderbird/93.0 Subject: Re: [PATCH] x86/smp: Factor out parts of native_smp_prepare_cpus() Content-Language: en-US To: Peter Zijlstra Cc: Boris Ostrovsky , xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, jgross@suse.com References: <1635896196-18961-1-git-send-email-boris.ostrovsky@oracle.com> <6a7edbff-e255-661d-c68f-c07b7519e421@oderland.se> From: Josef Johansson In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - office.oderland.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - oderland.se X-Get-Message-Sender-Via: office.oderland.com: authenticated_id: josjoh@oderland.se X-Authenticated-Sender: office.oderland.com: josjoh@oderland.se Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/11/21 11:15, Peter Zijlstra wrote: > On Wed, Nov 10, 2021 at 10:52:09PM +0100, Josef Johansson wrote: >> On 11/3/21 00:36, Boris Ostrovsky wrote: >>> Commit 66558b730f25 ("sched: Add cluster scheduler level for x86") >>> introduced cpu_l2c_shared_map mask which is expected to be initialized >>> by smp_op.smp_prepare_cpus(). That commit only updated >>> native_smp_prepare_cpus() version but not xen_pv_smp_prepare_cpus(). >>> As result Xen PV guests crash in set_cpu_sibling_map(). >>> >>> While the new mask can be allocated in xen_pv_smp_prepare_cpus() one can >>> see that both versions of smp_prepare_cpus ops share a number of common >>> operations that can be factored out. So do that instead. >>> >>> Fixes: 66558b730f25 ("sched: Add cluster scheduler level for x86") >>> Signed-off-by: Boris Ostrovsky >>> --- >>> arch/x86/include/asm/smp.h | 1 + >>> arch/x86/kernel/smpboot.c | 19 +++++++++++++------ >>> arch/x86/xen/smp_pv.c | 11 ++--------- >>> 3 files changed, 16 insertions(+), 15 deletions(-) >>> >>> diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h >>> index 08b0e90623ad..81a0211a372d 100644 >>> --- a/arch/x86/include/asm/smp.h >>> +++ b/arch/x86/include/asm/smp.h >>> @@ -126,6 +126,7 @@ static inline void arch_send_call_function_ipi_mask(const struct cpumask *mask) >>> >>> void cpu_disable_common(void); >>> void native_smp_prepare_boot_cpu(void); >>> +void smp_prepare_cpus_common(void); >>> void native_smp_prepare_cpus(unsigned int max_cpus); >>> void calculate_max_logical_packages(void); >>> void native_smp_cpus_done(unsigned int max_cpus); >>> diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c >>> index 8241927addff..d7429198c22f 100644 >>> --- a/arch/x86/kernel/smpboot.c >>> +++ b/arch/x86/kernel/smpboot.c >>> @@ -1350,12 +1350,7 @@ static void __init smp_get_logical_apicid(void) >>> cpu0_logical_apicid = GET_APIC_LOGICAL_ID(apic_read(APIC_LDR)); >>> } >>> >>> -/* >>> - * Prepare for SMP bootup. >>> - * @max_cpus: configured maximum number of CPUs, It is a legacy parameter >>> - * for common interface support. >>> - */ >>> -void __init native_smp_prepare_cpus(unsigned int max_cpus) >>> +void __init smp_prepare_cpus_common(void) >>> { >>> unsigned int i; >> Testing out this patch I got a warning that i is unused. Which it is, >> since for_each_possible_cpu(i) is removed. > Fixed. Can I add your Tested-by ? Yes, I tested with tip. Regards Josef