Received-SPF: pass (google.com: domain of linux-kernel+bounces-202752-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) client-ip=2604:1380:40f1:3f00::1;
Message-ID: <9f21c8e5-1103-44fa-82bd-cf608f8a96f6@redhat.com>
Date: Wed, 5 Jun 2024 16:05:19 +0200
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v5 1/2] sched/rt: Clean up usage of rt_task()
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Qais Yousef <qyousef@layalina.io>, Ingo Molnar <mingo@kernel.org>,
 Peter Zijlstra <peterz@infradead.org>, Juri Lelli <juri.lelli@redhat.com>,
 Steven Rostedt <rostedt@goodmis.org>,
 Vincent Guittot <vincent.guittot@linaro.org>,
 Thomas Gleixner <tglx@linutronix.de>,
 Alexander Viro <viro@zeniv.linux.org.uk>,
 Christian Brauner <brauner@kernel.org>,
 Andrew Morton <akpm@linux-foundation.org>, Jens Axboe <axboe@kernel.dk>,
 Metin Kaya <metin.kaya@arm.com>, linux-kernel@vger.kernel.org,
 linux-fsdevel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
 linux-mm@kvack.org, Phil Auld <pauld@redhat.com>
References: <20240604144228.1356121-1-qyousef@layalina.io>
 <20240604144228.1356121-2-qyousef@layalina.io>
 <b298bca1-190f-48a2-8d2c-58d54b879c72@redhat.com>
 <20240605093246.4h0kCR67@linutronix.de>
Content-Language: en-US, pt-BR, it-IT
From: Daniel Bristot de Oliveira <bristot@redhat.com>
In-Reply-To: <20240605093246.4h0kCR67@linutronix.de>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit

On 6/5/24 11:32, Sebastian Andrzej Siewior wrote:
> On 2024-06-04 17:57:46 [+0200], Daniel Bristot de Oliveira wrote:
>> On 6/4/24 16:42, Qais Yousef wrote:
>>> -	    (wakeup_rt && !dl_task(p) && !rt_task(p)) ||
>>> +	    (wakeup_rt && !realtime_task(p)) ||
>>
>> I do not like bikeshedding, and no hard feelings...
>>
>> But rt is a shortened version of realtime, and so it is making *it less*
>> clear that we also have DL here.
> 
> Can SCHED_DL be considered a real-time scheduling class as in opposite
> to SCHED_BATCH for instance? Due to its requirements it fits for a real
> time scheduling class, right?
> And RT (as in real time) already includes SCHED_RR and SCHED_FIFO.

It is a real-time scheduler, but the problem is that FIFO and RR are in rt.c and
they are called the "realtime" ones, so they are the first to come in mind.

-- Daniel

>> -- Daniel
> 
> Sebastian
>