linux-kernel - Re: [PATCH 09/14] bitmap: extend bitmap_{get,set}_value8() to bitmap_{get,set}

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <ZSZ6v1qgZbqKgKXa@smile.fi.intel.com>
Date:   Wed, 11 Oct 2023 13:36:47 +0300
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Alexander Lobakin <aleksander.lobakin@...el.com>
Cc:     Yury Norov <yury.norov@...il.com>,
        Rasmus Villemoes <linux@...musvillemoes.dk>,
        Alexander Potapenko <glider@...gle.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Eric Dumazet <edumazet@...gle.com>,
        David Ahern <dsahern@...nel.org>,
        Przemek Kitszel <przemyslaw.kitszel@...el.com>,
        Simon Horman <simon.horman@...igine.com>,
        netdev@...r.kernel.org, linux-btrfs@...r.kernel.org,
        dm-devel@...hat.com, ntfs3@...ts.linux.dev,
        linux-s390@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 09/14] bitmap: extend bitmap_{get,set}_value8() to
 bitmap_{get,set}_bits()

On Wed, Oct 11, 2023 at 11:33:25AM +0200, Alexander Lobakin wrote:
> From: Yury Norov <yury.norov@...il.com>
> Date: Mon, 9 Oct 2023 09:31:15 -0700
> 
> > + Alexander Potapenko <glider@...gle.com>
> > 
> > On Mon, Oct 09, 2023 at 05:10:21PM +0200, Alexander Lobakin wrote:
> >> Sometimes there's need to get a 8/16/...-bit piece of a bitmap at a
> >> particular offset. Currently, there are only bitmap_{get,set}_value8()
> >> to do that for 8 bits and that's it.
> > 
> > And also a series from Alexander Potapenko, which I really hope will
> > get into the -next really soon. It introduces bitmap_read/write which
> > can set up to BITS_PER_LONG at once, with no limitations on alignment
> > of position and length:
> > 
> > https://lore.kernel.org/linux-arm-kernel/ZRXbOoKHHafCWQCW@yury-ThinkPad/T/#mc311037494229647088b3a84b9f0d9b50bf227cb
> > 
> > Can you consider building your series on top of it?
> 
> Yeah, I mentioned in the cover letter that I'm aware of it and in fact
> it doesn't conflict much, as the functions I'm adding here get optimized
> as much as the original bitmap_{get,set}_value8(), while Alexander's
> generic helpers are heavier.
> I realize lots of calls will be optimized as well due to the offset and
> the width being compile-time constants, but not all of them. The idea of
> keeping two pairs of helpers initially came from Andy if I understood
> him correctly.

Just a disclaimer: The idea came before I saw the series by Alexander Potapenko.

> What do you think? I can provide some bloat-o-meter stats after
> rebasing. And either way, I see no issue in basing this series on top of
> Alex' one.

-- 
With Best Regards,
Andy Shevchenko