From: Thomas Gleixner <tglx@linutronix.de>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Ivo Sieben <meltedpianoman@gmail.com>,
RT <linux-rt-users@vger.kernel.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] RFC: Set irq thread to RT priority on creation
Date: Thu, 30 May 2013 21:50:41 +0200 (CEST) [thread overview]
Message-ID: <alpine.LFD.2.02.1305302147290.2905@ionos> (raw)
In-Reply-To: <1369925681.26799.6.camel@gandalf.local.home>
On Thu, 30 May 2013, Steven Rostedt wrote:
> On Thu, 2013-05-30 at 16:07 +0200, Thomas Gleixner wrote:
>
> > > This patch solves an issue for me where a device driver is expected to handle an
> > > interrupt immediatly after irq handlers are installed and interrupts enabled.
> >
> > You miss to explain what kind of issue that is.
>
> I could envision the case where the interrupt is initialized but doesn't
> go off until much later. If it never ran, then it would still be in
> SCHED_OTHER(), and that first interrupt could have a large delay.
Nope. As Ivo explained it's about an interrupt coming in right away,
i.e. before __setup_irq() reaches:
if (new->thread)
wake_up_process(new->thread);
The ones which come much later do not have that issue as the thread
code already sits in the waiting loop and already adjusted the
priority.
Thanks,
tglx
next prev parent reply other threads:[~2013-05-30 19:50 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-30 12:12 [PATCH] RFC: Set irq thread to RT priority on creation Ivo Sieben
2013-05-30 14:07 ` Thomas Gleixner
2013-05-30 14:54 ` Steven Rostedt
2013-05-30 19:50 ` Thomas Gleixner [this message]
2013-06-03 10:12 ` [PATCH-v2] " Ivo Sieben
2013-06-03 14:45 ` Thomas Gleixner
2013-06-05 6:46 ` Ivo Sieben
2013-06-14 15:33 ` Sebastian Andrzej Siewior
2013-05-30 14:53 ` [PATCH] RFC: " Steven Rostedt
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=alpine.LFD.2.02.1305302147290.2905@ionos \
--to=tglx@linutronix.de \
--cc=bigeasy@linutronix.de \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rt-users@vger.kernel.org \
--cc=meltedpianoman@gmail.com \
--cc=rostedt@goodmis.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).