From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Juri Lelli <juri.lelli@redhat.com>
Cc: linux-rt-users <linux-rt-users@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [RT] WARNING at hrtimer_start_range_ns
Date: Thu, 23 Jun 2022 12:46:35 +0200 [thread overview]
Message-ID: <YrREi3qSDfNek9S1@linutronix.de> (raw)
In-Reply-To: <YqnygxNWOztakt8+@localhost.localdomain>
On 2022-06-15 16:53:55 [+0200], Juri Lelli wrote:
> Hi,
Hi,
> My understanding is that we have
>
> fs/aio.c::read_events
> wait_event_interruptible_hrtimeout
> __wait_event_hrtimeout
> hrtimer_init_sleeper_on_stack <- this might mode |=HRTIMER_MODE_HARD on RT
will set HRTIMER_MODE_HARD of might set HRTIMER_MODE_HARD if the task has elevated priority
(RT/DL).
> hrtimer_start_range_ns
> WARN_ON_ONCE(!(mode & HRTIMER_MODE_HARD) ^ !timer->is_hard)
> fires since the latter doesn't see the change of mode done by
> init_sleeper
correct.
> The attached patch seems to cure the problem, although I'm not entirely
> sure it's the cleanest fix (if I'm right at all about it :).
The problem seems to be that __wait_event_hrtimeout() does
hrtimer_start_range_ns() instead of hrtimer_sleeper_start_expires(). So
if you switch that, then it should go away.
> Thanks,
> Juri
Sebastian
next prev parent reply other threads:[~2022-06-23 10:46 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-15 14:53 [RT] WARNING at hrtimer_start_range_ns Juri Lelli
2022-06-22 7:51 ` Juri Lelli
2022-06-23 10:46 ` Sebastian Andrzej Siewior [this message]
2022-06-23 13:47 ` Juri Lelli
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=YrREi3qSDfNek9S1@linutronix.de \
--to=bigeasy@linutronix.de \
--cc=juri.lelli@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rt-users@vger.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