All of lore.kernel.org
 help / color / mirror / Atom feed
From: Steven Rostedt <rostedt@goodmis.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Ingo Molnar <mingo@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>
Subject: Re: [patch 17/18] sched: Enable might_sleep() checks early
Date: Tue, 16 May 2017 09:14:12 -0400	[thread overview]
Message-ID: <20170516091412.77987500@gandalf.local.home> (raw)
In-Reply-To: <alpine.DEB.2.20.1705160923070.1934@nanos>

On Tue, 16 May 2017 09:33:52 +0200 (CEST)
Thomas Gleixner <tglx@linutronix.de> wrote:


> Darn, forgot about PREEMPT_VOLUNTARY and that excellent changelog does not
> mention it either. 
> 
> > So if we schedule to the kernel_init() task before we set kthreadd_task
> > we'll try and spawn kthreads and OOPS.  
> 
> So back to Stevens question. No, we can't set the state earlier than right
> before schedule() simply because with PREEMPT preemption _is_ actually
> disabled and kernel_kthread() will trigger might_sleep() splats.

So a comment in the code mentioning PREEMPT_VOLUNTARY might be
advantageous.

> 
> What a mess.

Indeed.

-- Steve

  reply	other threads:[~2017-05-16 13:14 UTC|newest]

Thread overview: 61+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-14 18:27 [patch 00/18] init: Enable might_sleep() and smp_processor_id() debugging early Thomas Gleixner
2017-05-14 18:27 ` [patch 01/18] init: Pin init task to boot cpu initially Thomas Gleixner
2017-05-15 14:10   ` Steven Rostedt
2017-05-14 18:27 ` [patch 02/18] arm: Adjust system_state check Thomas Gleixner
2017-05-14 18:27   ` Thomas Gleixner
2017-05-14 18:27 ` [patch 03/18] arm64: " Thomas Gleixner
2017-05-14 18:27   ` Thomas Gleixner
2017-05-14 18:27 ` [patch 04/18] x86/smp: " Thomas Gleixner
2017-05-15 14:17   ` Steven Rostedt
2017-05-14 18:27 ` [patch 05/18] metag: " Thomas Gleixner
2017-05-14 18:27   ` Thomas Gleixner
2017-05-14 18:27 ` [patch 06/18] powerpc: " Thomas Gleixner
2017-05-14 18:27   ` Thomas Gleixner
2017-05-15  9:19   ` Michael Ellerman
2017-05-14 18:27 ` [patch 07/18] ACPI: " Thomas Gleixner
2017-05-14 18:27   ` Thomas Gleixner
2017-05-15 10:20   ` Mark Rutland
2017-05-15 10:20     ` Mark Rutland
2017-05-15 10:25     ` Thomas Gleixner
2017-05-15 10:25       ` Thomas Gleixner
2017-05-15 14:27   ` Steven Rostedt
2017-05-16 18:13     ` Thomas Gleixner
2017-05-14 18:27 ` [patch 08/18] mm: " Thomas Gleixner
2017-05-15  6:18   ` Greg Kroah-Hartman
2017-05-15 14:33     ` Steven Rostedt
2017-05-14 18:27 ` [patch 09/18] cpufreq/pasemi: " Thomas Gleixner
2017-05-14 18:27   ` Thomas Gleixner
2017-05-15  5:24   ` Viresh Kumar
2017-05-15 14:34     ` Steven Rostedt
2017-05-14 18:27 ` [patch 10/18] iommu/vt-d: Adjust system_state checks Thomas Gleixner
2017-05-14 18:27   ` Thomas Gleixner
2017-05-15 14:42   ` Joerg Roedel
2017-05-14 18:27 ` [patch 11/18] iommu/of: Adjust system_state check Thomas Gleixner
2017-05-14 18:27   ` Thomas Gleixner
2017-05-15 10:45   ` Robin Murphy
2017-05-15 10:45     ` Robin Murphy
2017-05-15 14:42   ` Joerg Roedel
2017-05-15 14:42     ` Joerg Roedel
2017-05-14 18:27 ` [patch 12/18] async: Adjust system_state checks Thomas Gleixner
2017-05-14 18:39   ` Arjan van de Ven
2017-05-14 18:27 ` [patch 13/18] extable: " Thomas Gleixner
2017-05-15 14:37   ` Steven Rostedt
2017-05-14 18:27 ` [patch 14/18] printk: " Thomas Gleixner
2017-05-15 14:53   ` Steven Rostedt
2017-05-14 18:27 ` [patch 15/18] mm/vmscan: " Thomas Gleixner
2017-05-14 18:27   ` Thomas Gleixner
2017-05-15 14:54   ` Steven Rostedt
2017-05-15 14:54     ` Steven Rostedt
2017-05-14 18:27 ` [patch 16/18] init: Introduce SYSTEM_BOOTING_UP/SMP states Thomas Gleixner
2017-05-15  9:58   ` Juergen Gross
2017-05-15 14:58   ` Steven Rostedt
2017-05-14 18:27 ` [patch 17/18] sched: Enable might_sleep() checks early Thomas Gleixner
2017-05-15 15:10   ` Steven Rostedt
2017-05-15 19:12     ` Thomas Gleixner
2017-05-16  7:14       ` Peter Zijlstra
2017-05-16  7:33         ` Thomas Gleixner
2017-05-16 13:14           ` Steven Rostedt [this message]
2017-05-14 18:27 ` [patch 18/18] sched: Enable smp_processor_id() " Thomas Gleixner
2017-05-15 15:12   ` Steven Rostedt
2017-05-15 15:36     ` Thomas Gleixner
2017-05-15 11:53 ` [patch 00/18] init: Enable might_sleep() and smp_processor_id() debugging early Mark Rutland

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=20170516091412.77987500@gandalf.local.home \
    --to=rostedt@goodmis.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=mingo@kernel.org \
    --cc=peterz@infradead.org \
    --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.