From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
linux-kernel@vger.kernel.org,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Rik van Riel <riel@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [RFC PATCH] sched/cputime: drop local_irq_safe() in vtime_init_idle()
Date: Thu, 14 Apr 2016 15:41:17 +0200 [thread overview]
Message-ID: <570F9DFD.5080807@linutronix.de> (raw)
In-Reply-To: <20160414131827.GA7090@lerouge>
On 04/14/2016 03:18 PM, Frederic Weisbecker wrote:
> I think I tried this but I got lockdep warnings because the other updaters
> happen on IRQ.
I booted and played a little but lockdep didn't scream here so far.
> In practive we can't be interrupted since the idle task hasn't even started.
>
> Now we can probably get rid of the write_seqcount_stuff here because what
> is initialized there is supposed to be visible by the idle task once it runs.
>
> But I'm more worried about readers.
Most idle_thread_get() callers happen at boottime. Then I see two
during CPU-up (cpu-hotplug) at runtime. One from _cpu_up() via
idle_thread_get() and the second via bringup_cpu() and the second in
bringup_cpu().
Sebastian
next prev parent reply other threads:[~2016-04-14 13:41 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-14 12:29 [RFC PATCH] sched/cputime: drop local_irq_safe() in vtime_init_idle() Sebastian Andrzej Siewior
2016-04-14 13:07 ` Rik van Riel
2016-04-14 13:18 ` Frederic Weisbecker
2016-04-14 13:41 ` Sebastian Andrzej Siewior [this message]
2016-04-14 14:23 ` Frederic Weisbecker
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=570F9DFD.5080807@linutronix.de \
--to=bigeasy@linutronix.de \
--cc=a.p.zijlstra@chello.nl \
--cc=fweisbec@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=riel@redhat.com \
--cc=tglx@linutronix.de \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.