Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Wed, 7 Oct 2020 14:19:39 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Michal Hocko <mhocko@kernel.org>
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        Frederic Weisbecker <fweisbecker@suse.de>,
        LKML <linux-kernel@vger.kernel.org>,
        Mel Gorman <mgorman@suse.de>, Ingo Molnar <mingo@redhat.com>,
        Michal Hocko <mhocko@suse.com>
Subject: Re: [RFC PATCH] kernel: allow to configure PREEMPT_NONE,
 PREEMPT_VOLUNTARY on kernel command line
Message-ID: <20201007121939.GE2628@hirez.programming.kicks-ass.net>
References: <20201007120401.11200-1-mhocko@kernel.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20201007120401.11200-1-mhocko@kernel.org>
Precedence: bulk

On Wed, Oct 07, 2020 at 02:04:01PM +0200, Michal Hocko wrote:
> From: Michal Hocko <mhocko@suse.com>
> 
> Many people are still relying on pre built distribution kernels and so
> distributions have to provide mutliple kernel flavors to offer different
> preemption models. Most of them are providing PREEMPT_NONE for typical
> server deployments and PREEMPT_VOLUNTARY for desktop users.

Is there actually a benefit to NONE? We were recently talking about
removing it.

The much more interesting (runtime) switch (IMO) would be between
VOLUNTARY and PREEMPT.