From: Peter Zijlstra <peterz@infradead.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>,
LKML <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linuxfoundation.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Ingo Molnar <mingo@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Sebastian Siewior <bigeasy@linutronix.de>,
Paul McKenney <paulmck@linux.vnet.ibm.com>,
Christoph Hellwig <hch@lst.de>, Tejun Heo <tj@kernel.org>,
Lukas Bulwahn <lukas.bulwahn@gmail.com>,
Daniel Wagner <wagi@monom.org>,
Tom Zanussi <tom.zanussi@linux.intel.com>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
Clark Williams <clark.williams@gmail.com>,
Julia Cartwright <julia@ni.com>,
Marc Zyngier <marc.zyngier@arm.com>,
Frederic Weisbecker <frederic@kernel.org>
Subject: Re: [patch 1/1] Kconfig: Introduce CONFIG_PREEMPT_RT
Date: Wed, 17 Jul 2019 09:38:24 +0200 [thread overview]
Message-ID: <20190717073824.GT3419@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20190715150601.205143057@linutronix.de>
On Mon, Jul 15, 2019 at 05:04:03PM +0200, Thomas Gleixner wrote:
> Add a new entry to the preemption menu which enables the real-time support
> for the kernel. The choice is only enabled when an architecture supports
> it.
>
> It selects PREEMPT as the RT features depend on it. To achieve that the
> existing PREEMPT choice is renamed to PREEMPT_LL which select PREEMPT as
> well.
>
> No functional change.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
> arch/Kconfig | 3 +++
> kernel/Kconfig.preempt | 25 +++++++++++++++++++++++--
> 2 files changed, 26 insertions(+), 2 deletions(-)
>
> --- a/arch/Kconfig
> +++ b/arch/Kconfig
> @@ -809,6 +809,9 @@ config ARCH_NO_COHERENT_DMA_MMAP
> config ARCH_NO_PREEMPT
> bool
>
> +config ARCH_SUPPORTS_RT
> + bool
> +
> config CPU_NO_EFFICIENT_FFS
> def_bool n
>
> --- a/kernel/Kconfig.preempt
> +++ b/kernel/Kconfig.preempt
> @@ -35,10 +35,10 @@ config PREEMPT_VOLUNTARY
>
> Select this if you are building a kernel for a desktop system.
>
> -config PREEMPT
> +config PREEMPT_LL
> bool "Preemptible Kernel (Low-Latency Desktop)"
> depends on !ARCH_NO_PREEMPT
> - select PREEMPT_COUNT
> + select PREEMPT
> select UNINLINE_SPIN_UNLOCK if !ARCH_INLINE_SPIN_UNLOCK
> help
> This option reduces the latency of the kernel by making
> @@ -55,7 +55,28 @@ config PREEMPT
> embedded system with latency requirements in the milliseconds
> range.
>
> +config PREEMPT_RT
> + bool "Fully Preemptible Kernel (Real-Time)"
> + depends on EXPERT && ARCH_SUPPORTS_RT
> + select PREEMPT
> + help
> + This option turns the kernel into a real-time kernel by replacing
> + various locking primitives (spinlocks, rwlocks, etc) with
> + preemptible priority-inheritance aware variants, enforcing
> + interrupt threading and introducing mechanisms to break up long
> + non-preemtible sections. This makes the kernel, except for very
> + low level and critical code pathes (entry code, scheduler, low
> + level interrupt handling) fully preemtible and brings most
> + execution contexts under scheduler control.
> +
> + Select this if you are building a kernel for systems which
> + require real-time guarantees.
> +
> endchoice
>
> config PREEMPT_COUNT
> bool
> +
> +config PREEMPT
> + bool
> + select PREEMPT_COUNT
>
>
next prev parent reply other threads:[~2019-07-17 7:39 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-15 15:04 [patch 0/1] Kconfig: Introduce CONFIG_PREEMPT_RT Thomas Gleixner
2019-07-15 15:04 ` [patch 1/1] " Thomas Gleixner
2019-07-15 19:47 ` Lukas Bulwahn
2019-07-16 18:20 ` Paul E. McKenney
2019-07-16 20:07 ` Steven Rostedt
2019-07-16 20:10 ` Clark Williams
2019-07-16 20:18 ` Daniel Bristot de Oliveira
2019-07-16 20:59 ` Frederic Weisbecker
2019-07-16 22:58 ` Ingo Molnar
2019-07-16 23:34 ` Gratian Crisan
2019-07-17 7:38 ` Peter Zijlstra [this message]
2019-07-17 7:57 ` Marc Zyngier
2019-07-17 8:45 ` Daniel Wagner
2019-07-17 20:01 ` [patch V2 " Thomas Gleixner
2019-07-18 14:19 ` [tip:sched/urgent] sched/rt, " tip-bot for Thomas Gleixner
2019-07-18 14:50 ` [patch V2 1/1] " Julia Cartwright
2019-07-18 17:52 ` [tip:sched/urgent] sched/rt, " tip-bot for Thomas Gleixner
2019-07-18 19:23 ` [patch V2 1/1] " Tom Zanussi
2019-07-18 21:16 ` [tip:sched/urgent] sched/rt, " tip-bot for Thomas Gleixner
2019-07-17 23:05 ` [patch 1/1] " Luis Claudio R. Goncalves
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