linux-kernel - Re: [PATCH] block: simplify blksize

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] [day] [month] [year] [list]

Date:   Wed, 26 Oct 2022 10:34:35 -0600
From:   Keith Busch <kbusch@...nel.org>
To:     Bart Van Assche <bvanassche@....org>
Cc:     Dawei Li <set_pte_at@...look.com>, axboe@...nel.dk, hch@....de,
        linux-block@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] block: simplify blksize_bits() implementation

On Wed, Oct 26, 2022 at 09:29:21AM -0700, Bart Van Assche wrote:
> On 10/26/22 08:14, Dawei Li wrote:
> > Convert current looping-based implementation into bit operation,
> > which can bring improvement for:
> > 
> > 1) bitops is more efficient for its arch-level optimization.
> 
> As far as I know blksize_bits() is not used in the hot path so performance
> of this function is not critical.

blksize_bits() is used on every IO going through iomap_dio_bio_iter(),
though the usage there is completely unnecessary and can be removed.