From: "Michal Koutný" <mkoutny-IBi9RG/b67k@public.gmane.org>
To: Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>
Cc: Kairui Song <kasong-1Nz4purKYjRBDgjK7y7TUQ@public.gmane.org>,
Suren Baghdasaryan
<surenb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>,
Chengming Zhou
<zhouchengming-EC8Uxl6Npydl57MIdRCFDg@public.gmane.org>,
Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
Ingo Molnar <mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
Peter Zijlstra <peterz-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>,
cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Kairui Song <ryncsn-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Subject: Re: [PATCH 2/2] sched/psi: iterate through cgroups directly
Date: Wed, 8 Feb 2023 22:57:14 +0100 [thread overview]
Message-ID: <Y+QaunjOmvJf3NTU@blackbook> (raw)
In-Reply-To: <Y+P17OVZZWVpYIb0-druUgvl0LCNAfugRpC6u6w@public.gmane.org>
On Wed, Feb 08, 2023 at 02:20:12PM -0500, Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org> wrote:
> Hm, I don't think it does. It sets up *iter to point to the parent for
> the _next() call, but it returns task_dfl_cgroup()->psi. The next call
> does the same: cgroup = *iter, *iter = parent, return cgroup->psi.
You are right.
> It could be a bit more readable to have *iter always point to the
> current cgroup - but no strong preference either way from me:
A casually reading half-brain finds this more idiomatic :)
I just hope the "preloading" of the parent via iter isn't crucial to the
performance change.
Kairui, I like this reorganization and its effect!
Michal
next prev parent reply other threads:[~2023-02-08 21:57 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-08 16:16 [PATCH 0/2] sched/psi: Optimize PSI iteration Kairui Song
[not found] ` <20230208161654.99556-1-ryncsn-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2023-02-08 16:16 ` [PATCH 1/2] sched/psi: simplify cgroup psi retrieving Kairui Song
2023-02-08 17:17 ` Michal Koutný
[not found] ` <20230208161654.99556-2-ryncsn-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2023-02-08 18:54 ` Johannes Weiner
2023-02-08 16:16 ` [PATCH 2/2] sched/psi: iterate through cgroups directly Kairui Song
[not found] ` <20230208161654.99556-3-ryncsn-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2023-02-08 17:29 ` Michal Koutný
2023-02-08 19:20 ` Johannes Weiner
[not found] ` <Y+P17OVZZWVpYIb0-druUgvl0LCNAfugRpC6u6w@public.gmane.org>
2023-02-08 21:57 ` Michal Koutný [this message]
2023-02-09 16:08 ` Kairui Song
[not found] ` <CAMgjq7Bem+8g8A_OR26PHhYYx-A7LHHO3tyQNR_tMnaaKNxkug-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2023-02-15 17:49 ` Kairui Song
2023-02-15 18:25 ` Michal Koutný
2023-02-08 19:15 ` Johannes Weiner
2023-02-08 22:03 ` Michal Koutný
2023-02-09 15:30 ` Kairui Song
[not found] ` <Y+P0wLTdZcOPiKPZ-druUgvl0LCNAfugRpC6u6w@public.gmane.org>
2023-02-09 15:32 ` Kairui Song
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