Message-ID: <46212587-aac6-9513-70a2-32be7eeded14@bytedance.com>
Date:   Thu, 9 Feb 2023 14:01:16 +0000
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Subject: Re: [External] Re: [PATCH v7 0/9] Parallel CPU bringup for x86_64
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To:     David Woodhouse <dwmw2@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>, paulmck@kernel.org
Cc:     kim.phillips@amd.com, arjan@linux.intel.com, mingo@redhat.com,
        bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com,
        x86@kernel.org, pbonzini@redhat.com, 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
References: <20230207230436.2690891-1-usama.arif@bytedance.com>
 <20230209035300.GA3216394@paulmck-ThinkPad-P17-Gen-1>
 <8e2f03e2-9517-aeb4-df60-b36ef3ff3a75@bytedance.com>
 <f07b371ae2eb11f541c665b488b3d4b6bf1a81b3.camel@infradead.org>
 <87357f2gyd.ffs@tglx>
 <eea887fb7d634c24529743fce8295b2f78eb861d.camel@infradead.org>
 <76b8560c940f4506a690152e91e2f030eb24f86e.camel@infradead.org>
From:   Usama Arif <usama.arif@bytedance.com>
In-Reply-To: <76b8560c940f4506a690152e91e2f030eb24f86e.camel@infradead.org>
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On 09/02/2023 13:48, David Woodhouse wrote:
> On Thu, 2023-02-09 at 12:10 +0000, David Woodhouse wrote:
>> On Thu, 2023-02-09 at 12:53 +0100, Thomas Gleixner wrote:
>>> On Thu, Feb 09 2023 at 11:03, David Woodhouse wrote:
>>>> This one also fixes it for me. If we're happy with this approach, I'll
>>>> work it into Thomas's original patch (and hopefully eventually he'll be
>>>> happy enough with it and the commit message that he'll give us his
>>>> Signed-off-by for it.)
>>>
>>> I'm happy enough by now, but I'm not sure how much of the original patch
>>> is still left. Also you did the heavy lifting of making it work and
>>> writing the nice changelog. So please make this:
>>>
>>> From: David Woodhouse <dwmw2@infradead.org>
>>>
>>> Co-developed-by: Thomas Gleixner <tglx@linutronix.de>
>>> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
>>> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
>>
>> Thanks. I'll flip that to the Amazon address, of course. It's useless
>> for actual email (until I apply that LART some more) but I should still
>> use it for that.
>>
>> I think I'm going to make one more change to that as I review it; in
>> the "should never happen" case of not finding the APIC ID in the
>> cpuid_to_apicid[] array it would just keep searching for ever. I don't
>> know if there's a better thing to do other than just dropping the
>> trampoline lock and 1:cli;hlt;jmp 1b but at least it's *attempting* to
>> handle the failure.
>>
>> Patch below, and I'll update the tree shortly. There's a "what if
>> there's noise in the top 32 bits of %rcx" fix in there too.
> 
> All done and pushed out to parallel-6.2-rc7-part1 (and not -part1)
> branches. Usama, are you able to redo the testing and take it from
> here? Thanks for that; it's saving me a lot of time!
> 
Thanks! Will retest and repost now!

Usama

> 
> I'm mostly done for the week now as by this time tomorrow, I need to
> have the skis on the roof of the car and be ready to pick the family up
> from school and start driving south...