LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Pavel Machek <pavel@ucw.cz>
To: Andrew Morton <akpm@osdl.org>
Cc: Ingo Molnar <mingo@elte.hu>,
	rmk+lkml@arm.linux.org.uk, linux-kernel@vger.kernel.org
Subject: Re: [patch] fix emergency reboot: call reboot notifier list if possible
Date: Tue, 23 Jan 2007 19:57:12 +0000	[thread overview]
Message-ID: <20070123195712.GB6596@ucw.cz> (raw)
In-Reply-To: <20070117020343.8622e44d.akpm@osdl.org>

Hi!

> > > On Wed, Jan 17, 2007 at 10:13:19AM +0100, Ingo Molnar wrote:
> > > > we dont call the reboot notifiers during emergency reboot mainly because 
> > > > it could be called from atomic context and reboot notifiers are a 
> > > > blocking notifier list. But actually the kernel is often perfectly 
> > > > reschedulable in this stage, so we could as well process the 
> > > > reboot_notifier_list.
> > > 
> > > My experience has been that when there has been the need to use this
> > > facility, the kernel hasn't been reschedulable. [...]
> > 
> > this decision is totally automatic - so if your situation happens and 
> > the kernel isnt reschedulable, then the notifier chain wont be called 
> > and nothing changes from your perspective. Hm, perhaps this should be 
> > dependent on CONFIG_PREEMPT, to make sure preempt_count() is reliable?
> > 
> > but from my perspective this patch fixes a real regression.
> > 
> > updated patch attached below.
> > 
> 
> Making it dependent upon CONFIG_PREEMPT seems a bit sucky.  Perhaps pass in
> some "you were called from /proc/sysrq-trigger" notification?

What about adding 'B' with 'reboot with notifications' meaning?
							Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

  parent reply	other threads:[~2007-01-24 13:17 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-01-17  9:13 Ingo Molnar
2007-01-17  9:22 ` Russell King
2007-01-17  9:39   ` Ingo Molnar
2007-01-17 10:03     ` Andrew Morton
2007-01-17 10:25       ` Ingo Molnar
2007-01-23 19:57       ` Pavel Machek [this message]
2007-01-24 16:30         ` Randy Dunlap
2007-01-24 17:49           ` linux-os (Dick Johnson)
2007-01-17  9:51 ` [patch] KVM: do VMXOFF upon reboot Ingo Molnar
2007-01-17 10:02   ` Ingo Molnar
2007-01-21 10:17     ` Avi Kivity

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=20070123195712.GB6596@ucw.cz \
    --to=pavel@ucw.cz \
    --cc=akpm@osdl.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=rmk+lkml@arm.linux.org.uk \
    --subject='Re: [patch] fix emergency reboot: call reboot notifier list if possible' \
    /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

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).