linux-kernel - Re: [v2 1/5] lib/bitmap: add bitmap_{set,get}_value

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Date:   Fri, 14 Jul 2023 14:07:45 +0200
From:   Alexander Potapenko <glider@...gle.com>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc:     William Breathitt Gray <william.gray@...aro.org>,
        catalin.marinas@....com, will@...nel.org, pcc@...gle.com,
        andreyknvl@...il.com, linux@...musvillemoes.dk,
        yury.norov@...il.com, linux-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, eugenis@...gle.com
Subject: Re: [v2 1/5] lib/bitmap: add bitmap_{set,get}_value_unaligned()

On Fri, Jul 14, 2023 at 1:28 PM Andy Shevchenko
<andriy.shevchenko@...ux.intel.com> wrote:
>
> On Fri, Jul 14, 2023 at 07:19:15AM -0400, William Breathitt Gray wrote:
> > On Fri, Jul 14, 2023 at 11:04:16AM +0300, Andy Shevchenko wrote:
> > > On Thu, Jul 13, 2023 at 08:05:34PM +0200, Alexander Potapenko wrote:
> > > > On Thu, Jul 13, 2023 at 7:29 PM Andy Shevchenko
> > > > <andriy.shevchenko@...ux.intel.com> wrote:
> > > > > On Thu, Jul 13, 2023 at 02:57:01PM +0200, Alexander Potapenko wrote:
> > > > > > The two new functions allow setting/getting values of length up to
> > > > > > BITS_PER_LONG bits at arbitrary position in the bitmap.
> > > > >
> > > > > A couple of years (?) ago it was a series to achieve something like this with
> > > > > better (?) code. Why not resurrect that one?
> > > > >
> > > > > https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg2195426.html
> > > >
> > > > It looks more compact thanks to GENMASK, I can cook something based on
> > > > the proposed bitmap_{set,get}_value (and change the names if you
> > > > prefer the shorter ones).
> > > > But I'd better avoid pulling in the rest of that series without a strong need.
> > >
> > > William, what do you think on this?
> > >
> > > I'm personally prefer William's version as not only it was published first
> > > it was carefully designed and got a lot of review already. We just hadn't had
> > > the user for it that time.
> >
> > Yes, that version went through several revisions so it's been well
> > tested and known to work -- as you pointed out it just lacked the users
> > to warrant merging it into the tree. If it statisfies the use-case
> > required here now, then I think we should it pick it up rather than
> > reinvent the solution again.
> >
> > Also, we probably don't need the "clump" code in there, so perhaps
> > splitting it out to just the bitmap_{set,get}_value relevant code is
> > fine.
>
> Agree, thank you for your comments!
>
> --
> With Best Regards,
> Andy Shevchenko
>
>
So would it be fine if I split off bitmap_set_value() and
bitmap_get_value() from that series and send it (with the appropriate
attribution) instead of my patch 1/5?
We'll probably still need to retain patch 2/5 (with the function names changed).