linux-kernel - Re: [PATCH v4 1/5] lib/bitmap: add bitmap_{set,get}

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Date:   Fri, 22 Sep 2023 09:47:53 +0200
From:   Alexander Potapenko <glider@...gle.com>
To:     Yury Norov <yury.norov@...il.com>
Cc:     catalin.marinas@....com, will@...nel.org, pcc@...gle.com,
        andreyknvl@...il.com, andriy.shevchenko@...ux.intel.com,
        linux@...musvillemoes.dk, linux-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, eugenis@...gle.com,
        syednwaris@...il.com, william.gray@...aro.org,
        Arnd Bergmann <arnd@...db.de>
Subject: Re: [PATCH v4 1/5] lib/bitmap: add bitmap_{set,get}_value()

>
> Regarding the rest of the series:
>  - I still see Evgenii's name in mtecomp.c, and EA0 references;

Double-checked there are none in v5 (only the Suggested-by: tag)

>  - git-am throws warning about trailing line;

I checked locally that `git am` does not warn about v5 patches. But
given that the patches are generated with `git format-patch` I suspect
they get garbled when you download them, could it be the case?

>  - checkpatch warns 7 times;

It now warns 4 times, three warnings are about updating MAINTAINERS (I
don't think there's need for this), the last one is about
CONFIG_ARM64_MTE_COMP_KUNIT_TEST not having three lines of description
text in Kconfig.

> Can you fix all the above before sending the new version?

> Have you tested generic part against BE32, BE64 and LE32 architectures;
> and arch part against BE64? If not, please do.

I did now.


> You're mentioning that the compression ratio is 2 to 20x. Can you
> share the absolute numbers? If it's 1k vs 2k, I think most people
> just don't care...

In the other thread I mentioned that although 20x compression is
reachable, it may not lead to practical savings. I reworded the
description, having added the absolute numbers.

> Can you share the code that you used to measure the compression ratio?
> Would it make sense to export the numbers via sysfs?

Done in v5

> Thanks,
> Yury



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Alexander Potapenko
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