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Date:   Fri, 9 Oct 2020 13:26:43 +0200
From:   Michal Hocko <mhocko@suse.com>
To:     Peter Zijlstra <peterz@infradead.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>
Subject: Re: [RFC PATCH] kernel: allow to configure PREEMPT_NONE,
 PREEMPT_VOLUNTARY on kernel command line
Message-ID: <20201009112643.GM4967@dhcp22.suse.cz>
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On Fri 09-10-20 13:17:04, Michal Hocko wrote:
[...]
> +config PREEMPT_DYNAMIC
> +	bool "Allow boot time preemption model selection"

	depends on !ARCH_NO_PREEMPT

> +	depends on PREEMPT_NONE || PREEMPT_VOLUNTARY
> +	help
> +	  This option allows to define the preemption model on the kernel
> +	  command line parameter and thus override the default preemption
> +	  model defined during compile time.
> +
> +	  The feature is primarily interesting for Linux distributions which
> +	  provide a pre-built kernel binary to reduce the number of kernel
> +	  flavors they offer while still offering different usecases.
> +
> +	  The runtime overhead is negligible with JUMP_LABELS enabled but if
> +	  runtime patching is not available for the specific architecture then
> +	  the potential overhead should be considered.
> +
> +	  Select if you the same pre-built kernel should be used for both Server
> +	  and Desktop workloads.
> +
>  config PREEMPT_COUNT
>         bool
-- 
Michal Hocko
SUSE Labs