linux-kernel - Re: [RFC PATCH 00/10] x86: Allocate AVX512 xstate ondemand

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Message-Id: <e249390b-6f87-47f6-8676-fa727b2fa932@www.fastmail.com>
Date:   Fri, 03 Dec 2021 11:42:10 +0000
From:   "Jiaxun Yang" <jiaxun.yang@...goat.com>
To:     "Dave Hansen" <dave.hansen@...el.com>, x86@...nel.org
Cc:     "Thomas Gleixner" <tglx@...utronix.de>,
        "Ingo Molnar" <mingo@...hat.com>, bp@...en8.de,
        dave.hansen@...ux.intel.com, hpa@...or.com,
        chang.seok.bae@...el.com, linux-kernel@...r.kernel.org
Subject: Re: [RFC PATCH 00/10] x86: Allocate AVX512 xstate ondemand



在2021年12月3日十二月 上午12:58，Dave Hansen写道：
> On 12/2/21 4:45 PM, Jiaxun Yang wrote:
>> 在2021年12月3日十二月 上午12:40，Dave Hansen写道：
>>> On 12/2/21 4:36 PM, Jiaxun Yang wrote:
>>>> Also we are going to have heterogeneous processors that
>>>> only some cores support AVX512, it can be helpful when
>>>> dealing with such processors.
>>> Really?  Which x86 vendor is doing that?
>> Clear lower two bits of MSR 0xAF on Alder Lake give me some suprise :-)
>
> I honestly don't know what you're talking about.  Does poking that MSR
> allowing AVX512 instructions to be executed on cores where it was
> otherwise disabled?  That's entertaining, but it's far from "supported"
> or even support*able* in Linux.

If it's improper I'll drop the statement in commit message :-)

Yep, I'm entertaining with kernel hackcing.

Thanks

-- 
- Jiaxun