public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Ingo Molnar <mingo@elte.hu>
To: Don Zickus <dzickus@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>,
	x86@kernel.org, LKML <linux-kernel@vger.kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Robert Richter <robert.richter@amd.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	seiji.aguchi@hds.com, vgoyal@redhat.com, mjg@redhat.com,
	tony.luck@intel.com, gong.chen@intel.com, satoru.moriya@hds.com,
	avi@redhat.com
Subject: Re: [PATCH 1/3] x86, reboot:  Use NMI instead of REBOOT_VECTOR to stop cpus
Date: Wed, 12 Oct 2011 18:33:59 +0200	[thread overview]
Message-ID: <20111012163358.GD31857@elte.hu> (raw)
In-Reply-To: <20111012125442.GJ5795@redhat.com>


* Don Zickus <dzickus@redhat.com> wrote:

> On Wed, Oct 12, 2011 at 09:30:25AM +0200, Ingo Molnar wrote:
> > 
> > * Don Zickus <dzickus@redhat.com> wrote:
> > 
> > > +		if (register_nmi_handler(NMI_LOCAL, smp_stop_nmi_callback,
> > > +					 NMI_FLAG_FIRST, "smp_stop"))
> > > +			return;		/* return what? */
> > 
> > That comment looks a bit odd.
> 
> Yeah, I copied it from the kdump code because it seemed relevant.  
> The point was to express the paranoid concern, if we can't register 
> the NMI handler for whatever reason, what happens!?.  How do we 
> explain to anyone we failed to shut down the other cpus?
> 
> I can expand the comment to be more specific in the paranoia.  I 
> just wasn't sure the right way to handle that failure case.

Just add something like:

	/* Note: we ignore failures here */

if there's nothing intelligent possible.

Thanks,

	Ingo

  reply	other threads:[~2011-10-12 16:35 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-10-11 15:24 [PATCH 0/3] Use NMI to stop cpus Don Zickus
2011-10-11 15:24 ` [PATCH 1/3] x86, reboot: Use NMI instead of REBOOT_VECTOR " Don Zickus
2011-10-12  2:35   ` Chen Gong
2011-10-12 12:51     ` Don Zickus
2011-10-13  8:17       ` Chen Gong
2011-10-12  7:30   ` Ingo Molnar
2011-10-12 12:54     ` Don Zickus
2011-10-12 16:33       ` Ingo Molnar [this message]
2011-10-11 15:24 ` [PATCH 2/3] x86, NMI: Add NMI IPI selftest Don Zickus
2011-10-12  7:27   ` Ingo Molnar
2011-10-11 15:24 ` [PATCH 3/3] x86, NMI: knob to disable using NMI IPIs to stop cpus Don Zickus
2011-10-12  7:28   ` Ingo Molnar

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=20111012163358.GD31857@elte.hu \
    --to=mingo@elte.hu \
    --cc=akpm@linux-foundation.org \
    --cc=andi@firstfloor.org \
    --cc=avi@redhat.com \
    --cc=dzickus@redhat.com \
    --cc=gong.chen@intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mjg@redhat.com \
    --cc=peterz@infradead.org \
    --cc=robert.richter@amd.com \
    --cc=satoru.moriya@hds.com \
    --cc=seiji.aguchi@hds.com \
    --cc=tony.luck@intel.com \
    --cc=vgoyal@redhat.com \
    --cc=x86@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