On Wed, Oct 11, 2023 at 11:33:25AM +0200, Alexander Lobakin wrote:

From: Yury Norov <yury.norov@gmail.com>
Date: Mon, 9 Oct 2023 09:31:15 -0700

quoted

+ Alexander Potapenko [off-list ref]

On Mon, Oct 09, 2023 at 05:10:21PM +0200, Alexander Lobakin wrote:

quoted

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 (local)

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.
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.

You're right, let's try both and see what how worse is one comparing
to another wrt bloat-o-meter and overall code generation. If the
difference is not that terrible, I'd stick to universal and simpler
for users version.

If the difference is significant, we'd have to keep both. Maybe it's
worth to try merge the aligned case into generic one, but it's not the
purpose of your series, of course.

Thanks,
Yury