From: Tom Lendacky <thomas.lendacky@amd.com>
To: David Woodhouse <dwmw2@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, "H . Peter Anvin" <hpa@zytor.com>,
Paolo Bonzini <pbonzini@redhat.com>,
"Paul E . McKenney" <paulmck@kernel.org>,
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, Sean Christopherson <seanjc@google.com>,
Paul Menzel <pmenzel@molgen.mpg.de>
Subject: Re: [PATCH v4 0/9] Parallel CPU bringup for x86_64
Date: Mon, 7 Feb 2022 12:50:35 -0600 [thread overview]
Message-ID: <ea03061e-14aa-8159-4935-869f694a4715@amd.com> (raw)
In-Reply-To: <20220201205328.123066-1-dwmw2@infradead.org>
On 2/1/22 14:53, David Woodhouse wrote:
> 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 2-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.
> 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 :)
I'm no longer seeing crashes launching high vCPU-count guests with this
series.
Thanks,
Tom
>
> David Woodhouse (8):
> x86/apic/x2apic: Fix parallel handling of cluster_mask
> cpu/hotplug: Move idle_thread_get() to <linux/smpboot.h>
> 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
>
> [dwoodhou@i7 linux-2.6]$ git diff --stat v5.17-rc2..share/parallel-5.17-part1
> 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 | 73 ++++++++
> arch/x86/kernel/smpboot.c | 325 ++++++++++++++++++++++++----------
> 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, 442 insertions(+), 161 deletions(-)
>
>
>
next prev parent reply other threads:[~2022-02-07 18:54 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-01 20:53 [PATCH v4 0/9] Parallel CPU bringup for x86_64 David Woodhouse
2022-02-01 20:53 ` [PATCH v4 1/9] x86/apic/x2apic: Fix parallel handling of cluster_mask David Woodhouse
2022-02-01 20:53 ` [PATCH v4 2/9] cpu/hotplug: Move idle_thread_get() to <linux/smpboot.h> David Woodhouse
2022-02-01 20:53 ` [PATCH v4 3/9] cpu/hotplug: Add dynamic parallel bringup states before CPUHP_BRINGUP_CPU David Woodhouse
2022-02-01 20:53 ` [PATCH v4 4/9] x86/smpboot: Reference count on smpboot_setup_warm_reset_vector() David Woodhouse
2022-02-01 20:53 ` [PATCH v4 5/9] x86/smpboot: Split up native_cpu_up into separate phases and document them David Woodhouse
2022-02-01 20:53 ` [PATCH v4 6/9] x86/smpboot: Support parallel startup of secondary CPUs David Woodhouse
2022-02-01 20:53 ` [PATCH v4 7/9] x86/smpboot: Send INIT/SIPI/SIPI to secondary CPUs in parallel David Woodhouse
2022-02-01 20:53 ` [PATCH v4 8/9] x86/mtrr: Avoid repeated save of MTRRs on boot-time CPU bringup David Woodhouse
2022-02-01 20:53 ` [PATCH v4 9/9] x86/smpboot: Serialize topology updates for secondary bringup David Woodhouse
2022-02-07 18:50 ` Tom Lendacky [this message]
2023-02-01 14:40 ` [PATCH v4 0/9] Parallel CPU bringup for x86_64 Usama Arif
2023-02-01 15:08 ` David Woodhouse
2023-02-01 16:38 ` [External] " Usama Arif
2023-02-01 16:55 ` H. Peter Anvin
2023-02-01 17:12 ` David Woodhouse
2023-02-02 10:06 ` David Woodhouse
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