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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 20227C636CD for ; Fri, 10 Feb 2023 04:11:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231187AbjBJELM (ORCPT ); Thu, 9 Feb 2023 23:11:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52110 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229917AbjBJELK (ORCPT ); Thu, 9 Feb 2023 23:11:10 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 945D03C24; Thu, 9 Feb 2023 20:11:07 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 28004B823B8; Fri, 10 Feb 2023 04:11:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B4C72C433EF; Fri, 10 Feb 2023 04:11:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1676002264; bh=mw5QlU1yAxoxctzjzn6SCdph/DJlBUZBAIVrLjlGQ0A=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=EGrgk3+QVI4VAEoGbjsX4msiFiyVw1MpLxiudf+dbJ5a7a0VFyv6qXfWX/QwN5DXQ Zd0y3m4ZT8iFzyDamqNqwkZorj3XGRlXDga+L/zVlursvv6QTwpVvyfC47Ib1dc55Y vA1TURyOQLmdaRBUsoP8vYyQv061+iRl17SM/50UHOEdzTnXGxLP3ozWwzVKgFwMmB v8MRRTb13vrfGFGVl3mkKgqDeWKFew4vp3qRyUSGD4nK9qHhC/8MgE4HZICz4HZ5lm DeRX/3wdtxvaebIv2jrmcNs5AzB4tVb5vJP/h6TV+QESfDGHc+q5pk1OlspsWXepxJ 3Fi89k1eYROjA== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id CBB3A5C1B2A; Thu, 9 Feb 2023 20:11:03 -0800 (PST) Date: Thu, 9 Feb 2023 20:11:03 -0800 From: "Paul E. McKenney" To: Usama Arif Cc: dwmw2@infradead.org, tglx@linutronix.de, kim.phillips@amd.com, arjan@linux.intel.com, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, x86@kernel.org, pbonzini@redhat.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, rcu@vger.kernel.org, mimoja@mimoja.de, hewenliang4@huawei.com, thomas.lendacky@amd.com, seanjc@google.com, pmenzel@molgen.mpg.de, fam.zheng@bytedance.com, punit.agrawal@bytedance.com, simon.evans@bytedance.com, liangma@liangbit.com Subject: Re: [PATCH v8 0/9] Parallel CPU bringup for x86_64 Message-ID: <20230210041103.GO2948950@paulmck-ThinkPad-P17-Gen-1> Reply-To: paulmck@kernel.org References: <20230209154156.266385-1-usama.arif@bytedance.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230209154156.266385-1-usama.arif@bytedance.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 09, 2023 at 03:41:47PM +0000, Usama Arif wrote: > The major change over v7 is fixing CPU0 hotplug not working as reported by > Paul E. McKenney using rcu torture tests. This is fixed by setting up the > initial_gs, initial_stack and early_gdt_descr properly for this case. > > The improvement in boot time is the same as v7. This one passes moderate rcutorture testing. Thanx, Paul > Thanks, > Usama > > Changes across versions: > v2: Cut it back to just INIT/SIPI/SIPI in parallel for now, nothing more > v3: Clean up x2apic patch, add MTRR optimisation, lock topology update > in preparation for more parallelisation. > v4: Fixes to the real mode parallelisation patch spotted by SeanC, to > avoid scribbling on initial_gs in common_cpu_up(), and to allow all > 24 bits of the physical X2APIC ID to be used. That patch still needs > a Signed-off-by from its original author, who once claimed not to > remember writing it at all. But now we've fixed it, hopefully he'll > admit it now :) > v5: rebase to v6.1 and remeasure performance, disable parallel bringup > for AMD CPUs. > v6: rebase to v6.2-rc6, disabled parallel boot on amd as a cpu bug and > reused timer calibration for secondary CPUs. > v7: [David Woodhouse] iterate over all possible CPUs to find any existing > cluster mask in alloc_clustermask. (patch 1/9) > Keep parallel AMD support enabled in AMD, using APIC ID in CPUID leaf > 0x0B (for x2APIC mode) or CPUID leaf 0x01 where 8 bits are sufficient. > Included sanity checks for APIC id from 0x0B. (patch 6/9) > Removed patch for reusing timer calibration for secondary CPUs. > commit message and code improvements. > v8: Fix CPU0 hotplug by setting up the initial_gs, initial_stack and > early_gdt_descr. > Drop trampoline lock and bail if APIC ID not found in find_cpunr. > Code comments improved and debug prints added. > > David Woodhouse (9): > x86/apic/x2apic: Allow CPU cluster_mask to be populated in parallel > cpu/hotplug: Move idle_thread_get() to > cpu/hotplug: Add dynamic parallel bringup states before > CPUHP_BRINGUP_CPU > x86/smpboot: Reference count on smpboot_setup_warm_reset_vector() > x86/smpboot: Split up native_cpu_up into separate phases and document > them > x86/smpboot: Support parallel startup of secondary CPUs > x86/smpboot: Send INIT/SIPI/SIPI to secondary CPUs in parallel > x86/mtrr: Avoid repeated save of MTRRs on boot-time CPU bringup > x86/smpboot: Serialize topology updates for secondary bringup > > arch/x86/include/asm/realmode.h | 3 + > arch/x86/include/asm/smp.h | 14 +- > arch/x86/include/asm/topology.h | 2 - > arch/x86/kernel/acpi/sleep.c | 1 + > arch/x86/kernel/apic/apic.c | 2 +- > arch/x86/kernel/apic/x2apic_cluster.c | 130 ++++++---- > arch/x86/kernel/cpu/common.c | 6 +- > arch/x86/kernel/cpu/mtrr/mtrr.c | 9 + > arch/x86/kernel/head_64.S | 99 +++++++- > arch/x86/kernel/smpboot.c | 350 +++++++++++++++++++------- > arch/x86/realmode/init.c | 3 + > arch/x86/realmode/rm/trampoline_64.S | 14 ++ > arch/x86/xen/smp_pv.c | 4 +- > include/linux/cpuhotplug.h | 2 + > include/linux/smpboot.h | 7 + > kernel/cpu.c | 31 ++- > kernel/smpboot.c | 2 +- > kernel/smpboot.h | 2 - > 18 files changed, 521 insertions(+), 160 deletions(-) > > -- > 2.25.1 >