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Date:   Tue, 11 Feb 2020 08:54:43 -0500
From:   Steven Rostedt <rostedt@goodmis.org>
To:     =?UTF-8?B?546L6LSH?= <yun.wang@linux.alibaba.com>
Cc:     Ingo Molnar <mingo@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Juri Lelli <juri.lelli@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
        "open list:SCHEDULER" <linux-kernel@vger.kernel.org>,
        Tejun Heo <tj@kernel.org>, Li Zefan <lizefan@huawei.com>,
        Johannes Weiner <hannes@cmpxchg.org>, cgroups@vger.kernel.org
Subject: Re: [RFC] why can't dynamic isolation just like the static way
Message-ID: <20200211085443.2a112c03@gandalf.local.home>
In-Reply-To: <fed10a26-7423-23b5-316c-c74d354870dd@linux.alibaba.com>
References: <fed10a26-7423-23b5-316c-c74d354870dd@linux.alibaba.com>
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You forgot to include the cgroup maintainers.

-- Steve


On Tue, 11 Feb 2020 16:17:34 +0800
王贇 <yun.wang@linux.alibaba.com> wrote:

> Hi, folks
> 
> We are dealing with isolcpus these days and try to do the isolation
> dynamically.
> 
> The kernel doc lead us into the cpuset.sched_load_balance, it's fine
> to achieve the dynamic isolation with it, however we got problem with
> the systemd stuff.
> 
> It's keeping create cgroup with sched_load_balance enabled on default,
> while the cpus are overlapped with the isolated ones, which lead into
> sched domain rebuild and these cpus become non-isolated.
> 
> We're just looking forward an easy way to dynamic isolate some cpus,
> just like the isolation parameter, but sched_load_balance forcing us
> to dealing with the management of cgroups, we really don't get the
> point in here...
> 
> Why do we have to mix the isolation with cgroups? Why not just provide
> a proc entry to read cpumask and rebuild the domains?
> 
> Please let us know if there is any good reason to make the dynamic
> isolation in that way, appreciated in advance :-)
> 
> Regards,
> Michael Wang