Date:   Mon, 6 Feb 2023 16:51:09 +0100
From:   Michal =?iso-8859-1?Q?Koutn=FD?= <mkoutny@suse.com>
To:     Frederic Weisbecker <frederic@kernel.org>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Roman Gushchin <roman.gushchin@linux.dev>,
        Michal Hocko <mhocko@suse.com>,
        Marcelo Tosatti <mtosatti@redhat.com>,
        Leonardo <leobras@redhat.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Shakeel Butt <shakeelb@google.com>,
        Muchun Song <muchun.song@linux.dev>,
        Andrew Morton <akpm@linux-foundation.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>, cgroups@vger.kernel.org,
        linux-mm@kvack.org
Subject: Re: [PATCH 1/2] sched/isolation: Merge individual nohz_full features
 into a common housekeeping flag
Message-ID: <20230206155107.GA31453@blackbody.suse.cz>
References: <20230203232409.163847-1-frederic@kernel.org>
 <20230203232409.163847-2-frederic@kernel.org>
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Hello Frederic.

On Sat, Feb 04, 2023 at 12:24:08AM +0100, Frederic Weisbecker <frederic@ker=
nel.org> wrote:
> The individual isolation features turned on by nohz_full were initially
> split in order for each of them to be tunable through cpusets. However
> plans have changed in favour of an interface (be it cpusets or sysctl)
> grouping all these features to be turned on/off altogether.
> Then should the need ever arise, the interface can still be expanded
> to handle the individual isolation features.
>=20
> Therefore the current isolation split between tick/timer/workqueue/rcu/
> kthreads/misc doesn't make sense anymore.

Why it doesn't make sense? I think it's a useful annotation of
respective operations wrt CPU isolation.

The grouping you did into HK_TYPE_KERNEL_NOISE (or even coarser) should
IMO be done at the place where it'll be exposed into the favored
interface (like it's with nohz_full=3D).

Thanks,
Michal

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