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

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Message-ID: <ZLExRvCytbxBcUef@smile.fi.intel.com>
Date:   Fri, 14 Jul 2023 14:28:06 +0300
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     William Breathitt Gray <william.gray@...aro.org>
Cc:     Alexander Potapenko <glider@...gle.com>, 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 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