linux-kernel - Re: [PATCH 29/38] tick-sched: remove wrapper around __tick_nohz_task

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Date:	Tue, 15 Apr 2014 10:15:24 +0530
From:	Viresh Kumar <viresh.kumar@...aro.org>
To:	Frederic Weisbecker <fweisbec@...il.com>
Cc:	Thomas Gleixner <tglx@...utronix.de>,
	Lists linaro-kernel <linaro-kernel@...ts.linaro.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Arvind Chauhan <Arvind.Chauhan@....com>,
	Linaro Networking <linaro-networking@...aro.org>
Subject: Re: [PATCH 29/38] tick-sched: remove wrapper around __tick_nohz_task_switch()

On 15 April 2014 04:52, Frederic Weisbecker <fweisbec@...il.com> wrote:
> On Mon, Apr 14, 2014 at 09:53:51PM +0530, Viresh Kumar wrote:
>> __tick_nohz_task_switch() was called only from tick_nohz_task_switch() and there
>> is nothing much in tick_nohz_task_switch() as well. IOW, we don't need
>> unnecessary wrapper over __tick_nohz_task_switch() to be there. Merge all code
>> from __tick_nohz_task_switch() into tick_nohz_task_switch() and move it to
>> tick-sched.c.
>>
>> This also moves check for tick_nohz_tick_stopped() outside of irq_save()
>> context.
>
> No, the wrapper is there on purpose in order to optimize the full dynticks off case in
> the context switch path with the jump label'ed check on tick_nohz_full_enabled().

Just to clarify, you are saying that:

Wrapper was there to save an extra function call when tick_nohz_full_enabled()
returns false, as tick_nohz_task_switch() will be inlined ?

In this case probably we can move !can_stop_full_tick() as well to the wrapper ?
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