From patchwork Wed Dec 15 14:56:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: David Woodhouse X-Patchwork-Id: 12678507 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 98FC7C433EF for ; Wed, 15 Dec 2021 14:57:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243673AbhLOO5n (ORCPT ); Wed, 15 Dec 2021 09:57:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56646 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243648AbhLOO5M (ORCPT ); Wed, 15 Dec 2021 09:57:12 -0500 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 480C9C061757; Wed, 15 Dec 2021 06:57:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding: Content-Type:MIME-Version:Message-Id:Date:Subject:Cc:To:From:Reply-To: Content-ID:Content-Description:In-Reply-To:References; bh=P340VFo+4PrrAUQaheCNZWVztH0i3+oCk4D7HckAZkY=; b=U9RTLiGsf5f36zTBHdhGQRZzfA vLKPTDrqLnJ8zr4wpgXX6EweGnRqycbMic4oSiN35734GJ0vPyBv/OjxtFBpAeYFgj/Zkq2PT1PaW qyCh9xffpTqYIibTewVLaLWfkeW6UKRYuco+SL7DuXIDqB3/q+X8p+FJewTRAe3uOR8U0WMMWqcDE z+NQ7hmg1tMeVmikjhOwW0/rRNW3WUSs85+mxSu5oDRjmGdMcfCN0HmtmEf60GZ23afvisKsbbU1p AhyWeD/PvAWs9Aqy8REVLPLE4GmSqs4lkRGlU7TDUO62nPIXU0oHQCJU2qAs4hmCEhAoqZ5BLkDGj iZl4+Vaw==; Received: from i7.infradead.org ([2001:8b0:10b:1:21e:67ff:fecb:7a92]) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mxVhr-001WOs-3j; Wed, 15 Dec 2021 14:56:35 +0000 Received: from dwoodhou by i7.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mxVhq-0001Nd-Mi; Wed, 15 Dec 2021 14:56:34 +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 v3 0/9] Parallel CPU bringup for x86_64 Date: Wed, 15 Dec 2021 14:56:24 +0000 Message-Id: <20211215145633.5238-1-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 desiato.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Doing the INIT/SIPI/SIPI in parallel for all APs and *then* waiting for them shaves about 80% off the AP bringup time on a 96-thread socket Skylake box (EC2 c5.metal) — from about 500ms to 100ms. There are more wins to be had with further parallelisation, but this is the simple part. 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. David Woodhouse (8): x86/apic/x2apic: Fix parallel handling of cluster_mask 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: 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 Thomas Gleixner (1): x86/smpboot: Support parallel startup of secondary CPUs arch/x86/include/asm/realmode.h | 3 + arch/x86/include/asm/smp.h | 13 +- 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 | 108 +++++++----- arch/x86/kernel/cpu/common.c | 6 +- arch/x86/kernel/cpu/mtrr/mtrr.c | 9 + arch/x86/kernel/head_64.S | 71 ++++++++ arch/x86/kernel/smpboot.c | 324 ++++++++++++++++++++++++---------- 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 | 27 ++- kernel/smpboot.c | 2 +- kernel/smpboot.h | 2 - 18 files changed, 441 insertions(+), 159 deletions(-)