linux-kernel - Re: [PATCHv4 3/8] efi/x86: Implement support for unaccepted memory

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Message-ID: <Yl5nSSC4HpSWqfY7@zn.tnic>
Date:   Tue, 19 Apr 2022 09:39:53 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     "Kirill A. Shutemov" <kirill@...temov.name>
Cc:     "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
        Andy Lutomirski <luto@...nel.org>,
        Sean Christopherson <seanjc@...gle.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Joerg Roedel <jroedel@...e.de>,
        Ard Biesheuvel <ardb@...nel.org>,
        Andi Kleen <ak@...ux.intel.com>,
        Kuppuswamy Sathyanarayanan 
        <sathyanarayanan.kuppuswamy@...ux.intel.com>,
        David Rientjes <rientjes@...gle.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Tom Lendacky <thomas.lendacky@....com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Peter Zijlstra <peterz@...radead.org>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Ingo Molnar <mingo@...hat.com>,
        Varad Gautam <varad.gautam@...e.com>,
        Dario Faggioli <dfaggioli@...e.com>,
        Dave Hansen <dave.hansen@...el.com>,
        Brijesh Singh <brijesh.singh@....com>,
        Mike Rapoport <rppt@...nel.org>,
        David Hildenbrand <david@...hat.com>, x86@...nel.org,
        linux-mm@...ck.org, linux-coco@...ts.linux.dev,
        linux-efi@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCHv4 3/8] efi/x86: Implement support for unaccepted memory

On Tue, Apr 19, 2022 at 02:50:15AM +0300, Kirill A. Shutemov wrote:
> I find it strange that you go after <linux/bitmap.h> which has limited
> exposure while <linux/acpi.h> and <linux/efi.h> are there already.

Funny you should mention that:

https://lore.kernel.org/r/YlCKWhMJEMUgJmjF@zn.tnic

I *have* been working towards that but it's a losing whack-a-mole game
when you and others keep adding new stuff.

So no, we won't take a pile of changes and let the maintainer clean it
up afterwards.

> What do you want me to do here?

I think the stuff coming from the linux/ namespace you can simply copy
into a header in compressed/, like I've done with efi.h.

> // <asm/bitops.h>

The asm/ stuff can be put into a shared/ namespace header like the io
stuff you did.

> As 1 bit represents 2M, not all chunks can be represented in the bitmap
> and they have to be accepted. But the *goal* is to record unaccepted
> memory into bitmap. Some accepting is a side effect.
> 
> The early_accept_memory() name is just wrong.

Ok, how about process_unaccepted_memory(). It should be generic enough.

> Okay, I will do as you want, but I really hate it.

I find it really weird that you feel so strongly about it. If I would
have been asked to do it, I would've done it without even considering
it. But ok, since you feel so strongly about it, I've asked what the
other maintainers think.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette