linux-kernel - Re: [PATCH v5] do_wait: make PIDTYPE

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 for Android: free password hash cracker in your pocket

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

Date:   Sat, 13 Mar 2021 18:25:35 +0100
From:   Oleg Nesterov <oleg@...hat.com>
To:     "Eric W. Biederman" <ebiederm@...ssion.com>
Cc:     Jim Newsome <jnewsome@...project.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Christian Brauner <christian@...uner.io>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v5] do_wait: make PIDTYPE_PID case O(1) instead of O(n)

On 03/12, Eric W. Biederman wrote:
>
> I am going to kibitz just a little bit more.
>
> When I looked at this a second time it became apparent that using
> pid_task twice should actually be faster as it removes a dependent load
> caused by thread_group_leader, and replaces it by accessing two adjacent
> pointers in the same cache line.

Heh, I think this code should be optimized for the reader in the first place ;)

But as I said I won't argue, readability is very subjective, I am fine with your
version too.

Oleg.