linux-kernel - Re: regression: gpiolib: switch the line state notifier to atomic unexpected impact on performance

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: <CAMRc=MewC-7XFfWxPS7cmMycxo-62NDrUKFyjnnCbwqXQXWuZw@mail.gmail.com>
Date: Tue, 11 Mar 2025 12:45:51 +0100
From: Bartosz Golaszewski <brgl@...ev.pl>
To: David Jander <david@...tonic.nl>
Cc: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>, Kent Gibson <warthog618@...il.com>, 
	Linus Walleij <linus.walleij@...aro.org>, linux-gpio@...r.kernel.org, 
	linux-kernel@...r.kernel.org
Subject: Re: regression: gpiolib: switch the line state notifier to atomic
 unexpected impact on performance

On Tue, Mar 11, 2025 at 11:01 AM David Jander <david@...tonic.nl> wrote:
>
> On kernel 6.13, after git revert -n fcc8b637c542 time is back to what it was
> on 6.12.
>

Interestingly: I cannot reproduce it. Obviously gpiofind doesn't exist
in libgpiod v2 but I'm running gpiodetect with and without reverting
these changes and am getting roughly the same results: ~0.050s real
time for 1 up to 4 chips.

Any idea why that could be? Can you reproduce it with libgpiod v2 (I
don't know why that wouldn't be the case but worth double checking).

Bart