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Message-ID: <5ee5bf79-6cdc-4d1b-a19f-f0d5165a5f16@redhat.com>
Date: Wed, 17 Jan 2024 12:15:07 -0500
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Subject: Re: [RFC PATCH 0/8] cgroup/cpuset: Support RCU_NOCB on isolated
 partitions
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To: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.com>, Johannes Weiner <hannes@cmpxchg.org>,
 Frederic Weisbecker <frederic@kernel.org>, Jonathan Corbet <corbet@lwn.net>,
 "Paul E. McKenney" <paulmck@kernel.org>,
 Neeraj Upadhyay <quic_neeraju@quicinc.com>,
 Joel Fernandes <joel@joelfernandes.org>,
 Josh Triplett <josh@joshtriplett.org>, Boqun Feng <boqun.feng@gmail.com>,
 Steven Rostedt <rostedt@goodmis.org>,
 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
 Lai Jiangshan <jiangshanlai@gmail.com>, Zqiang <qiang.zhang1211@gmail.com>,
 Davidlohr Bueso <dave@stgolabs.net>, Shuah Khan <shuah@kernel.org>,
 cgroups@vger.kernel.org, linux-doc@vger.kernel.org,
 linux-kernel@vger.kernel.org, rcu@vger.kernel.org,
 linux-kselftest@vger.kernel.org, Mrunal Patel <mpatel@redhat.com>,
 Ryan Phillips <rphillips@redhat.com>, Brent Rowsell <browsell@redhat.com>,
 Peter Hunt <pehunt@redhat.com>, Cestmir Kalina <ckalina@redhat.com>,
 Nicolas Saenz Julienne <nsaenz@kernel.org>,
 Alex Gladkov <agladkov@redhat.com>, Marcelo Tosatti <mtosatti@redhat.com>,
 Phil Auld <pauld@redhat.com>, Paul Gortmaker <paul.gortmaker@windriver.com>,
 Daniel Bristot de Oliveira <bristot@kernel.org>,
 Juri Lelli <juri.lelli@redhat.com>, Peter Zijlstra <peterz@infradead.org>,
 Costa Shulyupin <cshulyup@redhat.com>
References: <20240117163511.88173-1-longman@redhat.com>
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From: Waiman Long <longman@redhat.com>
In-Reply-To: <ZagJPoEsLZ6Dg-NG@mtj.duckdns.org>
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On 1/17/24 12:07, Tejun Heo wrote:
> Hello,
>
> On Wed, Jan 17, 2024 at 11:35:03AM -0500, Waiman Long wrote:
>> The first 2 patches are adopted from Federic with minor twists to fix
>> merge conflicts and compilation issue. The rests are for implementing
>> the new cpuset.cpus.isolation_full interface which is essentially a flag
>> to globally enable or disable full CPU isolation on isolated partitions.
> I think the interface is a bit premature. The cpuset partition feature is
> already pretty restrictive and makes it really clear that it's to isolate
> the CPUs. I think it'd be better to just enable all the isolation features
> by default. If there are valid use cases which can't be served without
> disabling some isolation features, we can worry about adding the interface
> at that point.

My current thought is to make isolated partitions act like 
isolcpus=domain, additional CPU isolation capabilities are optional and 
can be turned on using isolation_full. However, I am fine with making 
all these turned on by default if it is the consensus.

Cheers,
Longman