linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: luca abeni <luca.abeni@unitn.it>
To: Juri Lelli <juri.lelli@arm.com>, linux-kernel@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Subject: Question about prio_changed_dl()
Date: Fri, 19 Feb 2016 13:43:45 +0100	[thread overview]
Message-ID: <20160219134345.70ff4aa0@utopia> (raw)

Hi,

when playing with the __dl_{add,sub}_ac() stuff recently posted by
Juri, I found something that looks strange in prio_changed_dl():

static void prio_changed_dl(struct rq *rq, struct task_struct *p,
			    int oldprio)
{
	if (task_on_rq_queued(p) || rq->curr == p) {
		[...]
	} else
		switched_to_dl(rq, p);
}
but switched_to_dl() does:
static void switched_to_dl(struct rq *rq, struct task_struct *p)
{
	if (task_on_rq_queued(p) && rq->curr != p) {
		[...]
	}
}

so, prio_changed_dl() invokes switched_to_dl() if task_on_rq_queued()
is false, but in this case switched_to_dl() does nothing... Am I
missing something, or the
	} else
		switched_to_dl(rq, p);
is useless?
(BTW, it seems to me that switched_to_dl() is never invoked, for some
reason...)


			Thanks,
				Luca

If you wonder how this is related to __dl_{add,sub}_ac(), I am going to
write an email about it in a short time :)

             reply	other threads:[~2016-02-19 12:43 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-19 12:43 luca abeni [this message]
2016-02-25 14:01 ` Question about prio_changed_dl() Peter Zijlstra
2016-02-25 14:16   ` Juri Lelli
2016-02-25 14:25   ` luca abeni
2016-02-25 14:52     ` Peter Zijlstra
2016-02-27 11:37       ` luca abeni
2016-03-02 19:02         ` Peter Zijlstra
2016-03-02 20:16           ` luca abeni
2016-03-02 20:58             ` Peter Zijlstra
2016-03-04  8:50           ` luca abeni
2016-02-29 11:19   ` [tip:sched/core] sched/deadline: Remove superfluous call to switched_to_dl() tip-bot for Peter Zijlstra

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=20160219134345.70ff4aa0@utopia \
    --to=luca.abeni@unitn.it \
    --cc=juri.lelli@arm.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=peterz@infradead.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;
as well as URLs for NNTP newsgroup(s).