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Subject: Re: [PATCH v2 1/8] lib/find_bit.c: Add find_last_zero_bit
To:     Yun Levi <ppbuk5246@gmail.com>,
        Greg KH <gregkh@linuxfoundation.org>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Yury Norov <yury.norov@gmail.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        richard.weiyang@linux.alibaba.com, christian.brauner@ubuntu.com,
        Arnd Bergmann <arnd@arndb.de>,
        Josh Poimboeuf <jpoimboe@redhat.com>, rdunlap@infradead.org,
        masahiroy@kernel.org, peterz@infradead.org,
        peter.enderborg@sony.com, krzk@kernel.org,
        Brendan Higgins <brendanhiggins@google.com>,
        Kees Cook <keescook@chromium.org>, broonie@kernel.org,
        matti.vaittinen@fi.rohmeurope.com, mhiramat@kernel.org,
        jpa@git.mail.kapsi.fi, nivedita@alum.mit.edu,
        Alexander Potapenko <glider@google.com>, orson.zhai@unisoc.com,
        Takahiro Akashi <takahiro.akashi@linaro.org>, clm@fb.com,
        Josef Bacik <josef@toxicpanda.com>, dsterba@suse.com,
        dushistov@mail.ru,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
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On 6.12.20 г. 10:56 ч., Yun Levi wrote:
>> This, and the change above this, are not related to this patch so you
>> might not want to include them.
> 
>> Also, why is this patch series even needed?  I don't see a justification
>> for it anywhere, only "what" this patch is, not "why".
> 
> I think the find_last_zero_bit will help to improve in
> 7th patch's change and It can be used in the future.
> But if my thinking is bad.. Please let me know..
> 
> Thanks.
> Levi.
> 

btrfs' free space cache v1 is going to be removed some time in the
future so introducing kernel-wide change just for its own sake is a bit
premature. Also do you have measurements showing it indeed improves
performances?