linux-kernel - Re: [PATCH 3/9] all: replace bitmap_weigth() with bitmap

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <YaMJ7x8viyKyYk6w@qmqm.qmqm.pl>
Date:   Sun, 28 Nov 2021 05:47:43 +0100
From:   Michał Mirosław <mirq-linux@...e.qmqm.pl>
To:     Yury Norov <yury.norov@...il.com>
Cc:     linux-kernel@...r.kernel.org,
        bcm-kernel-feedback-list@...adcom.com, kvm@...r.kernel.org,
        linux-alpha@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-crypto@...r.kernel.org, linux-csky@...r.kernel.org,
        linux-ia64@...r.kernel.org, linux-mips@...r.kernel.org,
        linux-mm@...ck.org, linux-perf-users@...r.kernel.org,
        linux-riscv@...ts.infradead.org, linux-s390@...r.kernel.org,
        linux-snps-arc@...ts.infradead.org, linuxppc-dev@...ts.ozlabs.org
Subject: Re: [PATCH 3/9] all: replace bitmap_weigth() with
 bitmap_{empty,full,eq,gt,le}

On Sat, Nov 27, 2021 at 07:56:58PM -0800, Yury Norov wrote:
> bitmap_weight() counts all set bits in the bitmap unconditionally.
> However in some cases we can traverse a part of bitmap when we
> only need to check if number of set bits is greater, less or equal
> to some number.
> 
> This patch replaces bitmap_weight() with one of
> bitmap_{empty,full,eq,gt,le), as appropriate.
> 
> In some places driver code has been optimized further, where it's
> trivial.
[...]

I think this patch needs to be split. bitmap_full/empty() conversions
can be separated (don't need the bitmap_weight_*() functions) and
not all changes are trivial. Besides, gathering and checking all the
acks needed into one patch seems problematic.

Best Regards,
Michał Mirosław