From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <valentin.schneider@arm.com>
References: <20200914204209.256266093@linutronix.de> <20200914204441.794954043@linutronix.de>
From: Valentin Schneider <valentin.schneider@arm.com>
Subject: Re: [patch 08/13] sched: Clenaup PREEMPT_COUNT leftovers
In-reply-to: <20200914204441.794954043@linutronix.de>
Date: Wed, 16 Sep 2020 11:56:23 +0100
Message-ID: <jhj8sda56so.mognet@arm.com>
MIME-Version: 1.0
Content-Type: text/plain
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>, linux-arch@vger.kernel.org, Linus Torvalds <torvalds@linuxfoundation.org>, Sebastian Andrzej Siewior <bigeasy@linutronix.de>, 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>, Steven Rostedt <rostedt@goodmis.org>, Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>, Daniel Bristot de Oliveira <bristot@redhat.com>, Richard Henderson <rth@twiddle.net>, Ivan Kokshaysky <ink@jurassic.park.msu.ru>, Matt Turner <mattst88@gmail.com>, linux-alpha@vger.kernel.org, Jeff Dike <jdike@addtoit.com>, Richard Weinberger <richard@nod.at>, Anton Ivanov <anton.ivanov@cambridgegreys.com>, linux-um@lists.infradead.org, Brian Cain <bcain@codeaurora.org>, linux-hexagon@vger.kernel.org, Geert Uytterhoeven <geert@linux-m68k.org>, linux-m68k@lists.linux-m68k.org, Ingo Molnar <mingo@kernel.org>, Will Deacon <will@kernel.org>, Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org, Russell King <linux@armlinux.org.uk>, linux-arm-kernel@lists.infradead.org, Chris Zankel <chris@zankel.net>, Max Filippov <jcmvbkbc@gmail.com>, linux-xtensa@linux-xtensa.org, Jani Nikula <jani.nikula@linux.intel.com>, Joonas Lahtinen <joonas.lahtinen@linux.intel.com>, Rodrigo Vivi <rodrigo.vivi@intel.com>, David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, "Paul E. McKenney" <paulmck@kernel.org>, Josh Triplett <josh@joshtriplett.org>, Mathieu Desnoyers <mathieu.desnoyers@efficios.com>, Lai Jiangshan <jiangshanlai@gmail.com>, Shuah Khan <shuah@kernel.org>, rcu@vger.kernel.org, linux-kselftest@vger.kernel.org
List-ID: <linux-um.lists.infradead.org>


On 14/09/20 21:42, Thomas Gleixner wrote:
> CONFIG_PREEMPT_COUNT is now unconditionally enabled and will be
> removed. Cleanup the leftovers before doing so.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Juri Lelli <juri.lelli@redhat.com>
> Cc: Vincent Guittot <vincent.guittot@linaro.org>
> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Ben Segall <bsegall@google.com>
> Cc: Mel Gorman <mgorman@suse.de>
> Cc: Daniel Bristot de Oliveira <bristot@redhat.com>

Small nit below;

Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>

> ---
>  kernel/sched/core.c |    6 +-----
>  lib/Kconfig.debug   |    1 -
>  2 files changed, 1 insertion(+), 6 deletions(-)
>
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -3706,8 +3706,7 @@ asmlinkage __visible void schedule_tail(
>        * finish_task_switch() for details.
>        *
>        * finish_task_switch() will drop rq->lock() and lower preempt_count
> -	 * and the preempt_enable() will end up enabling preemption (on
> -	 * PREEMPT_COUNT kernels).

I suppose this wanted to be s/PREEMPT_COUNT/PREEMPT/ in the first place,
which ought to be still relevant.

> +	 * and the preempt_enable() will end up enabling preemption.
>        */
>
>       rq = finish_task_switch(prev);