From: Oleg Nesterov <oleg@redhat.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Jim Newsome <jnewsome@torproject.org>,
Andrew Morton <akpm@linux-foundation.org>,
Christian Brauner <christian@brauner.io>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5] do_wait: make PIDTYPE_PID case O(1) instead of O(n)
Date: Sat, 13 Mar 2021 18:25:35 +0100 [thread overview]
Message-ID: <20210313172534.GA3588@redhat.com> (raw)
In-Reply-To: <m1k0qcglol.fsf@fess.ebiederm.org>
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.
prev parent reply other threads:[~2021-03-13 17:26 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-12 17:38 [PATCH v5] do_wait: make PIDTYPE_PID case O(1) instead of O(n) Jim Newsome
2021-03-12 18:22 ` Andrew Morton
2021-03-12 18:39 ` Jim Newsome
2021-03-12 18:47 ` Andrew Morton
2021-03-13 2:42 ` Jim Newsome
2021-03-12 20:01 ` Jim Newsome
2021-03-12 20:29 ` Eric W. Biederman
2021-03-12 21:05 ` Jim Newsome
2021-03-12 21:25 ` Eric W. Biederman
2021-03-13 17:25 ` Oleg Nesterov [this message]
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