From:   Thomas Gleixner <tglx@linutronix.de>
To:     Usama Arif <usama.arif@bytedance.com>, dwmw2@infradead.org,
        kim.phillips@amd.com
Cc:     arjan@linux.intel.com, 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 v8 9/9] x86/smpboot: Serialize topology updates for
 secondary bringup
In-Reply-To: <20230209154156.266385-10-usama.arif@bytedance.com>
References: <20230209154156.266385-1-usama.arif@bytedance.com>
 <20230209154156.266385-10-usama.arif@bytedance.com>
Date:   Mon, 13 Feb 2023 21:43:13 +0100
Message-ID: <87v8k5s3dq.ffs@tglx>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

On Thu, Feb 09 2023 at 15:41, Usama Arif wrote:
> From: David Woodhouse <dwmw@amazon.co.uk>
>
> The toplogy update is performed by the AP via smp_callin() after the BSP
> has called do_wait_cpu_initialized(), setting the AP's bit in
> cpu_callout_mask to allow it to proceed.
>
> In preparation to enable further parallelism of AP bringup, add locking to
> serialize the update even if multiple APs are (in future) permitted to
> proceed through the next stages of bringup in parallel.

This one is also only relevant for further parallelisation, right?

Thanks,

        tglx