From:   Thomas Gleixner <tglx@linutronix.de>
To:     Usama Arif <usama.arif@bytedance.com>, dwmw2@infradead.org,
        arjan@linux.intel.com
Cc:     mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com,
        hpa@zytor.com, x86@kernel.org, pbonzini@redhat.com,
        paulmck@kernel.org, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org, rcu@vger.kernel.org, mimoja@mimoja.de,
        hewenliang4@huawei.com, thomas.lendacky@amd.com, seanjc@google.com,
        pmenzel@molgen.mpg.de, fam.zheng@bytedance.com,
        punit.agrawal@bytedance.com, simon.evans@bytedance.com,
        liangma@liangbit.com, David Woodhouse <dwmw@amazon.co.uk>,
        Usama Arif <usama.arif@bytedance.com>
Subject: Re: [PATCH v6 08/11] x86/smpboot: Send INIT/SIPI/SIPI to secondary
 CPUs in parallel
In-Reply-To: <20230202215625.3248306-9-usama.arif@bytedance.com>
References: <20230202215625.3248306-1-usama.arif@bytedance.com>
 <20230202215625.3248306-9-usama.arif@bytedance.com>
Date:   Tue, 07 Feb 2023 01:28:25 +0100
Message-ID: <87mt5qwc7q.ffs@tglx>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

On Thu, Feb 02 2023 at 21:56, Usama Arif wrote:

> From: David Woodhouse <dwmw@amazon.co.uk>
>
> When the APs can find their own APIC ID without assistance, we can do

We can do nothing ... Again, read Documentation/process ...

> the AP bringup in parallel.
>  /**
>   * arch_disable_smp_support() - disables SMP support for x86 at runtime
>   */
> @@ -1550,6 +1560,10 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
>  		do_parallel_bringup = false;
>  	}
>  
> +	if (do_parallel_bringup)
> +		cpuhp_setup_state_nocalls(CPUHP_BP_PARALLEL_DYN, "x86/cpu:kick",
> +					  native_cpu_kick, NULL);

https://www.kernel.org/doc/html/latest/process/maintainer-tip.html#bracket-rules

Thanks,

        tglx