From patchwork Thu Dec 9 15:09:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Woodhouse X-Patchwork-Id: 12666707 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 C36BAC433EF for ; Thu, 9 Dec 2021 15:10:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239279AbhLIPNk (ORCPT ); Thu, 9 Dec 2021 10:13:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42990 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234445AbhLIPNj (ORCPT ); Thu, 9 Dec 2021 10:13:39 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ECD08C061746; Thu, 9 Dec 2021 07:10:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Sender:Content-Transfer-Encoding: MIME-Version:Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-Type: Content-ID:Content-Description:In-Reply-To:References; bh=Va8s2nesZ5VZPw32CYfVQw20nzizZ9oKz+lpuPZMQw8=; b=DMw/9HVnFZG17EK6kvf2fIaU5S nQGN6/RzzTMZMdLZatkx4/OuPYjFR5irrPfj3qHLa/wKSZ0GpmN2WHkhwOhreWlbLKCLzr/BIvOwQ 5+lqKL64DKb0xJYsshV7T0C12LqJA3NRdQoUQ73skjEiWmq+vScMBVIvf0w3gqIvA+fKrnYPDwCZz Wbfl/cz7ZVU1CQ+pg20WzcP3ejQUdbCWetRp/qeQ/drjt65wplLbl7EqkzcNgCS+vxORXdYOQMJzS +7by5rLJmQ+tUp1PCvihhgIi3rX4W0CMW4i7LsgyPMeKJNOoyUsKaoOS3IEoWY9p4Q7OjK4ha4w5W yszgna5A==; Received: from i7.infradead.org ([2001:8b0:10b:1:21e:67ff:fecb:7a92]) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mvL3J-009Rs1-2U; Thu, 09 Dec 2021 15:09:45 +0000 Received: from dwoodhou by i7.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mvL3J-0000xk-83; Thu, 09 Dec 2021 15:09:45 +0000 From: David Woodhouse To: Thomas Gleixner Cc: Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Paolo Bonzini , "Paul E. McKenney" , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, rcu@vger.kernel.org, mimoja@mimoja.de, hewenliang4@huawei.com, hushiyuan@huawei.com, luolongjun@huawei.com, hejingxian@huawei.com Subject: [PATCH 00/11] Parallel CPU bringup for x86_64 Date: Thu, 9 Dec 2021 15:09:27 +0000 Message-Id: <20211209150938.3518-1-dwmw2@infradead.org> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Sender: David Woodhouse X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Dusting off this patch series from February, in which we reduce the time taken for bringing up CPUs on a 96-way Skylake box from 500ms to about 34ms. There is more parallelism to be had here, including a 1:many TSC sync (or just *no* TSC sync, in the kexec case), and letting the APs all run through their own states from CPUHP_BRINGUP_CPU to CPUHP_AP_ONLINE_IDLE in parallel too. But I'll take a mere factor of 15 for the time being. We can also have a careful look at the remaining time spent in the initial INIT/SIPI phase and see what we can shave off it. David Woodhouse (10): x86/apic/x2apic: Fix parallel handling of cluster_mask rcu: Kill rnp->ofl_seq and use only rcu_state.ofl_lock for exclusion rcu: Add mutex for rcu boost kthread spawning and affinity setting 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 cpu/hotplug: Move idle_thread_get() to x86/tsc: Avoid synchronizing TSCs with multiple CPUs in parallel x86/smp: Bring up secondary CPUs in parallel x86/kvm: Silence per-cpu pr_info noise about KVM clocks and steal time Thomas Gleixner (1): x86/boot: Support parallel startup of secondary CPUs arch/x86/include/asm/realmode.h | 3 +++ arch/x86/include/asm/smp.h | 9 ++++++- arch/x86/kernel/acpi/sleep.c | 1 + arch/x86/kernel/apic/apic.c | 2 +- arch/x86/kernel/apic/x2apic_cluster.c | 82 +++++++++++++++++++++++++++++++++++++------------------------- arch/x86/kernel/head_64.S | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ arch/x86/kernel/kvm.c | 6 ++--- arch/x86/kernel/kvmclock.c | 2 +- arch/x86/kernel/smpboot.c | 243 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++------------------------------------------------- arch/x86/kernel/tsc_sync.c | 7 ++++++ arch/x86/realmode/init.c | 3 +++ arch/x86/realmode/rm/trampoline_64.S | 14 +++++++++++ include/linux/cpuhotplug.h | 2 ++ include/linux/smpboot.h | 7 ++++++ kernel/cpu.c | 27 +++++++++++++++++++-- kernel/rcu/tree.c | 65 ++++++++++++++++++++++++------------------------- kernel/rcu/tree.h | 7 +++--- kernel/rcu/tree_plugin.h | 10 ++++++-- kernel/smpboot.c | 2 +- kernel/smpboot.h | 2 -- 20 files changed, 418 insertions(+), 147 deletions(-)