public inbox for linux-trace-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Steven Rostedt <rostedt@goodmis.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Ingo Molnar <mingo@redhat.com>,
	x86@kernel.org, Kees Cook <kees@kernel.org>,
	bpf@vger.kernel.org, Tejun Heo <tj@kernel.org>,
	Julia Lawall <Julia.Lawall@inria.fr>,
	Nicolas Palix <nicolas.palix@imag.fr>,
	cocci@inria.fr, "H. Peter Anvin" <hpa@zytor.com>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH] sched/core: Introduce task_*() helpers for PF_ flags
Date: Mon, 28 Apr 2025 08:12:20 -0400	[thread overview]
Message-ID: <20250428081220.1f3f2165@gandalf.local.home> (raw)
In-Reply-To: <aA0pDUDQViCA1hwi@gmail.com>

On Sat, 26 Apr 2025 20:42:21 +0200
Ingo Molnar <mingo@kernel.org> wrote:

> I'll send out a full series if there's no better suggestions for the 
> general approach.

Fine, you can take over. I have other things to work on.

Unless you add a task_user() or something similar that makes it very easy
to see that a task is a user thread other than testing if it's not a kernel
thread, it doesn't solve the issue that was my original motivation for my
patches. That is, there's places in the code that needs to only work on
user threads, and it would be nice to quickly see that the if statement is
checking if it is or not.

We have places that check if it's a kernel thread to exit out early:

	if (task_kernel(task))
		goto out;

And places that do something if it's a user thread:

	if (task_user(task))
		// do something special

By explicitly stating "user" in the test, makes that very easy to see,
where as:

	if (task_kernel(task))
		goto out;

and

	if (!task_kernel(task))
		// do something special

makes you have to look a bit harder. The kernel is complex enough, I
believe we should make it easier where there's low hanging fruit to do so.

-- Steve

      parent reply	other threads:[~2025-04-28 12:12 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-04-25 20:41 [RFC][PATCH 0/2] Add is_user_thread() and is_kernel_thread() helper functions Steven Rostedt
2025-04-25 20:41 ` [RFC][PATCH 1/2] kthread: " Steven Rostedt
2025-04-25 23:03   ` Kees Cook
2025-04-26 12:36     ` Steven Rostedt
2025-04-26 11:08   ` Borislav Petkov
2025-04-26 12:37     ` Steven Rostedt
2025-04-25 20:41 ` [RFC][PATCH 2/2] treewide: Have the task->flags & PF_KTHREAD check use the " Steven Rostedt
2025-04-25 23:09   ` Kees Cook
2025-04-26  3:22     ` Alexei Starovoitov
2025-04-28 18:34       ` Tejun Heo
2025-04-25 23:14 ` [RFC][PATCH 0/2] Add is_user_thread() and is_kernel_thread() " Andrew Morton
2025-04-26 10:41   ` Julia Lawall
2025-04-26 12:43   ` Steven Rostedt
2025-04-26 18:42     ` [PATCH] sched/core: Introduce task_*() helpers for PF_ flags Ingo Molnar
2025-04-26 18:51       ` Ingo Molnar
2025-04-26 20:06       ` Steven Rostedt
2025-04-28 12:12       ` Steven Rostedt [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20250428081220.1f3f2165@gandalf.local.home \
    --to=rostedt@goodmis.org \
    --cc=Julia.Lawall@inria.fr \
    --cc=akpm@linux-foundation.org \
    --cc=bpf@vger.kernel.org \
    --cc=cocci@inria.fr \
    --cc=hpa@zytor.com \
    --cc=kees@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-trace-kernel@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=mathieu.desnoyers@efficios.com \
    --cc=mhiramat@kernel.org \
    --cc=mingo@kernel.org \
    --cc=mingo@redhat.com \
    --cc=nicolas.palix@imag.fr \
    --cc=peterz@infradead.org \
    --cc=tglx@linutronix.de \
    --cc=tj@kernel.org \
    --cc=torvalds@linux-foundation.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox