Message-ID: <174e3a17-31bb-d74c-6248-23558fc2b5ee@igalia.com>
Date:   Tue, 28 Feb 2023 09:04:39 -0300
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Subject: Re: [PATCH v12 00/11] Parallel CPU bringup for x86_64
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To:     Paul Menzel <pmenzel@molgen.mpg.de>
Cc:     Usama Arif <usama.arif@bytedance.com>,
        David Woodhouse <dwmw2@infradead.org>,
        Arjan van de Ven <arjan@linux.intel.com>,
        Borislav Petkov <bp@alien8.de>, brgerst@gmail.com,
        dave.hansen@linux.intel.com, fam.zheng@bytedance.com,
        hewenliang4@huawei.com, "H. Peter Anvin" <hpa@zytor.com>,
        kim.phillips@amd.com, kvm@vger.kernel.org,
        LKML <linux-kernel@vger.kernel.org>,
        Ingo Molnar <mingo@redhat.com>, liangma@liangbit.com,
        mimoja@mimoja.de, oleksandr@natalenko.name,
        "Paul E. McKenney" <paulmck@kernel.org>,
        Paolo Bonzini <pbonzini@redhat.com>, piotrgorski@cachyos.org,
        punit.agrawal@bytedance.com, rcu@vger.kernel.org,
        Sean Christopherson <seanjc@google.com>,
        simon.evans@bytedance.com, Thomas Gleixner <tglx@linutronix.de>,
        Tom Lendacky <Thomas.Lendacky@amd.com>, x86@kernel.org
References: <3ca3b60e-47a2-640a-cad3-e3e110d3aaf7@igalia.com>
 <8b0cc6fa-8d40-7401-b8f9-559b5db3e8c9@molgen.mpg.de>
From:   "Guilherme G. Piccoli" <gpiccoli@igalia.com>
In-Reply-To: <8b0cc6fa-8d40-7401-b8f9-559b5db3e8c9@molgen.mpg.de>
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On 28/02/2023 07:13, Paul Menzel wrote:
> Dear Guilherme,
> 
> 
> Am 27.02.23 um 22:39 schrieb Guilherme G. Piccoli:
> 
>> I've tested it on Steam Deck (with and without the "no_parallel_bringup"
>> parameter), it works fine - also tested S3/deep sleep-resume cycle.
>>
>> Feel free to add (to the series):
>> Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
> 
> Thank you for testing the series. It’d be great if you could share the 
> timing differences.
> 
> […]
> 
> 
> Kind regards,
> 
> Paul

Hi Paul!

The results...weren't so great, I felt no difference heh
Which is also not bad, it seems the series favors big SMP systems, Deck
has only 8 CPUs.

But maybe the way I measured is not ideal? I just compared timestamps on
dmesg from the first SMP message up to the one that says the boot of
secondary CPUs is complete. Do you have a better suggestion? I can try
things here.

Cheers,


Guilherme