Re: [PATCH v5 7/7] sched/fair: Fair server interface

From: Daniel Bristot de Oliveira <bristot@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>,
	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>,
	Valentin Schneider <vschneid@redhat.com>,
	linux-kernel@vger.kernel.org,
	Luca Abeni <luca.abeni@santannapisa.it>,
	Tommaso Cucinotta <tommaso.cucinotta@santannapisa.it>,
	Thomas Gleixner <tglx@linutronix.de>,
	Joel Fernandes <joel@joelfernandes.org>,
	Vineeth Pillai <vineeth@bitbyteword.org>,
	Shuah Khan <skhan@linuxfoundation.org>,
	Phil Auld <pauld@redhat.com>
Subject: Re: [PATCH v5 7/7] sched/fair: Fair server interface
Date: Tue, 7 Nov 2023 14:24:28 +0100	[thread overview]
Message-ID: <51ed888b-591a-40aa-9de4-29cf4a84dd69@kernel.org> (raw)
In-Reply-To: <20231107123818.GV8262@noisy.programming.kicks-ass.net>

On 11/7/23 13:38, Peter Zijlstra wrote:
> On Sat, Nov 04, 2023 at 11:59:24AM +0100, Daniel Bristot de Oliveira wrote:
>> Add an interface for fair server setup on debugfs.
>>
>> Each rq have three files under /sys/kernel/debug/sched/rq/CPU{ID}:
>>
>>  - fair_server_runtime: set runtime in ns
>>  - fair_server_period: set period in ns
>>  - fair_server_defer: on/off for the defer mechanism
>>
>> Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
>> ---
> 
> I did the below, that gives us:
> 
> /debug/sched/fair_server/cpuX/{runtime,period,defer}

right!

> I wanted to also add:
> 
> /debug/sched/fair_server/{runtime,period,defer}
> 
> to more easily set all CPUs to the same value, but then figured
> userspace will just have to loop.

I thought about that too... and had the same conclusion... let 'em loop.

-- Daniel