kvm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: David Woodhouse <dwmw2@infradead.org>
To: Tom Lendacky <thomas.lendacky@amd.com>,
	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
Subject: Re: [PATCH v3 0/9] Parallel CPU bringup for x86_64
Date: Thu, 16 Dec 2021 19:24:56 +0000	[thread overview]
Message-ID: <ca0751c864570015ffe4d8cccdc94e0a5ef3086d.camel@infradead.org> (raw)
In-Reply-To: <761c1552-0ca0-403b-3461-8426198180d0@amd.com>

[-- Attachment #1: Type: text/plain, Size: 1054 bytes --]

On Thu, 2021-12-16 at 10:27 -0600, Tom Lendacky wrote:
> On 12/15/21 8:56 AM, 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 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.
> 
> I applied this series and began booting a regular non-SEV guest and hit a 
> failure at 39 vCPUs. No panic or warning, just a reset and OVMF was 
> executing again. I'll try to debug what's going, but not sure how quickly 
> I'll arrive at anything.

Thanks for testing. This is working for me with BIOS and EFI boots in
qemu and real hardware but it's mostly been Intel so far. I'll try
harder on an AMD box.

Anything else special about your setup, kernel config or qemu
invocation that might help me reproduce?

If it can repro without KVM, 'qemu -d in_asm' can be extremely useful
for this kind of thing btw.

[-- Attachment #2: smime.p7s --]
[-- Type: application/pkcs7-signature, Size: 5174 bytes --]

  reply	other threads:[~2021-12-16 19:25 UTC|newest]

Thread overview: 57+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-15 14:56 [PATCH v3 0/9] Parallel CPU bringup for x86_64 David Woodhouse
2021-12-15 14:56 ` [PATCH v3 1/9] x86/apic/x2apic: Fix parallel handling of cluster_mask David Woodhouse
2021-12-15 14:56 ` [PATCH v3 2/9] cpu/hotplug: Move idle_thread_get() to <linux/smpboot.h> David Woodhouse
2021-12-15 14:56 ` [PATCH v3 3/9] cpu/hotplug: Add dynamic parallel bringup states before CPUHP_BRINGUP_CPU David Woodhouse
2021-12-15 14:56 ` [PATCH v3 4/9] x86/smpboot: Reference count on smpboot_setup_warm_reset_vector() David Woodhouse
2021-12-15 14:56 ` [PATCH v3 5/9] x86/smpboot: Split up native_cpu_up into separate phases and document them David Woodhouse
2021-12-15 14:56 ` [PATCH v3 6/9] x86/smpboot: Support parallel startup of secondary CPUs David Woodhouse
2021-12-16 14:24   ` Tom Lendacky
2021-12-16 18:24     ` David Woodhouse
2021-12-16 19:00       ` Tom Lendacky
2021-12-16 19:20         ` David Woodhouse
2022-01-29 12:04           ` David Woodhouse
2022-01-31 13:59             ` Borislav Petkov
2022-02-01 10:25               ` David Woodhouse
2022-02-01 10:56                 ` Borislav Petkov
2022-02-01 12:39                   ` David Woodhouse
2022-02-01 12:56                     ` Borislav Petkov
2022-02-01 13:02                       ` David Woodhouse
2021-12-15 14:56 ` [PATCH v3 7/9] x86/smpboot: Send INIT/SIPI/SIPI to secondary CPUs in parallel David Woodhouse
2021-12-15 14:56 ` [PATCH v3 8/9] x86/mtrr: Avoid repeated save of MTRRs on boot-time CPU bringup David Woodhouse
2021-12-15 14:56 ` [PATCH v3 9/9] x86/smpboot: Serialize topology updates for secondary bringup David Woodhouse
2021-12-16 16:27 ` [PATCH v3 0/9] Parallel CPU bringup for x86_64 Tom Lendacky
2021-12-16 19:24   ` David Woodhouse [this message]
2021-12-16 22:52     ` Tom Lendacky
2021-12-17  0:13       ` David Woodhouse
2021-12-17 10:09         ` Igor Mammedov
2021-12-17 15:40           ` David Woodhouse
2021-12-20 17:10           ` David Woodhouse
2021-12-20 18:54             ` Tom Lendacky
2021-12-20 21:29               ` David Woodhouse
2021-12-20 21:47                 ` Tom Lendacky
2021-12-21 22:25                   ` Tom Lendacky
2021-12-21 22:33                     ` David Woodhouse
2021-12-17 17:48         ` Tom Lendacky
2021-12-17 19:11           ` David Woodhouse
2021-12-17 19:26             ` David Woodhouse
2021-12-17 20:15               ` Tom Lendacky
2021-12-17 19:46             ` Tom Lendacky
2021-12-17 20:13               ` David Woodhouse
2021-12-17 20:55                 ` Tom Lendacky
2021-12-17 22:48                   ` David Woodhouse
2022-01-28  9:54                   ` David Woodhouse
2022-01-28 21:40                     ` Sean Christopherson
2022-01-28 21:48                       ` David Woodhouse
2022-01-29  9:22                       ` David Woodhouse
2021-12-16 19:52   ` David Woodhouse
2021-12-16 19:55     ` Tom Lendacky
2021-12-16 19:59       ` David Woodhouse
2021-12-27 16:57 ` Paul Menzel
2021-12-28 11:34   ` Paul Menzel
2021-12-28 14:18     ` David Woodhouse
2021-12-29 13:18       ` Paul Menzel
2021-12-29 13:54         ` David Woodhouse
2022-02-14 13:45           ` Paul Menzel
2022-04-21 10:00             ` Mimoja
2022-04-22 21:19               ` Tom Lendacky
2022-06-01  8:30                 ` David Woodhouse

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=ca0751c864570015ffe4d8cccdc94e0a5ef3086d.camel@infradead.org \
    --to=dwmw2@infradead.org \
    --cc=bp@alien8.de \
    --cc=dave.hansen@linux.intel.com \
    --cc=hejingxian@huawei.com \
    --cc=hewenliang4@huawei.com \
    --cc=hpa@zytor.com \
    --cc=hushiyuan@huawei.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luolongjun@huawei.com \
    --cc=mimoja@mimoja.de \
    --cc=mingo@redhat.com \
    --cc=paulmck@kernel.org \
    --cc=pbonzini@redhat.com \
    --cc=rcu@vger.kernel.org \
    --cc=tglx@linutronix.de \
    --cc=thomas.lendacky@amd.com \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).