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From: Bernhard Walle <bwalle@suse.de>
To: Vivek Goyal <vgoyal@in.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	k-miyoshi@cb.jp.nec.com, kexec@lists.infradead.org,
	Takenori Nagano <t-nagano@ah.jp.nec.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [patch] add kdump_after_notifier
Date: Thu, 26 Jul 2007 17:34:40 +0200	[thread overview]
Message-ID: <20070726153440.GA19095@suse.de> (raw)
In-Reply-To: <20070726153240.GA15969@in.ibm.com>

* Vivek Goyal <vgoyal@in.ibm.com> [2007-07-26 17:32]:
> On Thu, Jul 26, 2007 at 04:07:02PM +0200, Bernhard Walle wrote:
> > * Takenori Nagano <t-nagano@ah.jp.nec.com> [2007-07-19 14:15]:
> > > 
> > > In latest kernel, we can't use panic_notifier_list if kdump is enabled.
> > > panic_notifier_list is very useful function for debug, failover, etc...
> > > 
> > > So this patch adds a control file /proc/sys/kernel/dump_after_notifier
> > > and resolves a problem users can not use both kdump and panic_notifier_list
> > > at the same time.
> > > 
> > > kdump_after_notifier = 0
> > >  -> panic()
> > >     -> crash_kexec(NULL)
> > > 
> > > kdump_after_notifier = 1
> > >  -> panic()
> > >     -> atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
> > >     -> crash_kexec(NULL)
> > 
> > What's problematic about this patch? I also would like to see that
> > feature.
> 
> I would like to see the code which will get executed after panic and 
> before crash_kexec(). This potentially makes crash dump feature unreliable
> in the sense one can now register on panic_notifier_list and try to
> do whole lot of things and might get stuck there. After the system
> has crashed, one is not supposed to do a whole lot.

Of course, but that's why the patch doesn't change this by default but
gives the user the choice.


Thanks,
   Bernhard

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WARNING: multiple messages have this Message-ID (diff)
From: Bernhard Walle <bwalle@suse.de>
To: Vivek Goyal <vgoyal@in.ibm.com>
Cc: Takenori Nagano <t-nagano@ah.jp.nec.com>,
	kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
	k-miyoshi@cb.jp.nec.com,
	Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [patch] add kdump_after_notifier
Date: Thu, 26 Jul 2007 17:34:40 +0200	[thread overview]
Message-ID: <20070726153440.GA19095@suse.de> (raw)
In-Reply-To: <20070726153240.GA15969@in.ibm.com>

* Vivek Goyal <vgoyal@in.ibm.com> [2007-07-26 17:32]:
> On Thu, Jul 26, 2007 at 04:07:02PM +0200, Bernhard Walle wrote:
> > * Takenori Nagano <t-nagano@ah.jp.nec.com> [2007-07-19 14:15]:
> > > 
> > > In latest kernel, we can't use panic_notifier_list if kdump is enabled.
> > > panic_notifier_list is very useful function for debug, failover, etc...
> > > 
> > > So this patch adds a control file /proc/sys/kernel/dump_after_notifier
> > > and resolves a problem users can not use both kdump and panic_notifier_list
> > > at the same time.
> > > 
> > > kdump_after_notifier = 0
> > >  -> panic()
> > >     -> crash_kexec(NULL)
> > > 
> > > kdump_after_notifier = 1
> > >  -> panic()
> > >     -> atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
> > >     -> crash_kexec(NULL)
> > 
> > What's problematic about this patch? I also would like to see that
> > feature.
> 
> I would like to see the code which will get executed after panic and 
> before crash_kexec(). This potentially makes crash dump feature unreliable
> in the sense one can now register on panic_notifier_list and try to
> do whole lot of things and might get stuck there. After the system
> has crashed, one is not supposed to do a whole lot.

Of course, but that's why the patch doesn't change this by default but
gives the user the choice.


Thanks,
   Bernhard

  reply	other threads:[~2007-07-26 15:34 UTC|newest]

Thread overview: 77+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-07-19 12:15 [patch] add kdump_after_notifier Takenori Nagano
2007-07-19 12:15 ` Takenori Nagano
2007-07-26 14:07 ` Bernhard Walle
2007-07-26 14:07   ` Bernhard Walle
2007-07-26 15:32   ` Vivek Goyal
2007-07-26 15:32     ` Vivek Goyal
2007-07-26 15:34     ` Bernhard Walle [this message]
2007-07-26 15:34       ` Bernhard Walle
2007-07-26 15:44       ` Vivek Goyal
2007-07-26 15:44         ` Vivek Goyal
2007-07-26 15:47         ` Bernhard Walle
2007-07-26 15:47           ` Bernhard Walle
2007-07-26 15:54           ` Vivek Goyal
2007-07-26 15:54             ` Vivek Goyal
2007-07-26 16:14             ` Bernhard Walle
2007-07-26 16:14               ` Bernhard Walle
2007-07-26 16:21               ` Bernhard Walle
2007-07-26 16:21                 ` Bernhard Walle
2007-07-26 23:28             ` Takenori Nagano
2007-07-26 23:28               ` Takenori Nagano
2007-07-30  9:16               ` Vivek Goyal
2007-07-30  9:16                 ` Vivek Goyal
2007-07-30 13:42                 ` Eric W. Biederman
2007-07-30 13:42                   ` Eric W. Biederman
2007-07-31  5:55                   ` Takenori Nagano
2007-07-31  5:55                     ` Takenori Nagano
2007-07-31  6:53                     ` Eric W. Biederman
2007-07-31  6:53                       ` Eric W. Biederman
2007-08-01  9:26                       ` Takenori Nagano
2007-08-01  9:26                         ` Takenori Nagano
2007-08-01 10:00                         ` Eric W. Biederman
2007-08-01 10:00                           ` Eric W. Biederman
2007-08-02  8:11                           ` Takenori Nagano
2007-08-02  8:11                             ` Takenori Nagano
2007-08-02 11:28                           ` Vivek Goyal
2007-08-02 11:28                             ` Vivek Goyal
2007-08-03  4:05                             ` Keith Owens
2007-08-03  4:05                               ` Keith Owens
2007-08-03  6:25                               ` Andrew Morton
2007-08-03  6:25                                 ` Andrew Morton
2007-08-03  6:34                                 ` Keith Owens
2007-08-03  6:34                                   ` Keith Owens
2007-08-03  7:37                                   ` Andrew Morton
2007-08-03  7:37                                     ` Andrew Morton
2007-08-03  7:10                                 ` Eric W. Biederman
2007-08-03  7:10                                   ` Eric W. Biederman
2007-08-05 11:07                               ` Vivek Goyal
2007-08-05 11:07                                 ` Vivek Goyal
2007-08-14  8:34                                 ` Takenori Nagano
2007-08-14  8:34                                   ` Takenori Nagano
2007-08-14  8:37                                   ` Bernhard Walle
2007-08-14  8:37                                     ` Bernhard Walle
2007-08-14  8:48                                     ` Takenori Nagano
2007-08-14  8:48                                       ` Takenori Nagano
2007-08-14  8:53                                       ` Bernhard Walle
2007-08-14  8:53                                         ` Bernhard Walle
2007-08-14 13:24                                     ` Vivek Goyal
2007-08-14 13:24                                       ` Vivek Goyal
2007-08-16  9:26                                       ` Takenori Nagano
2007-08-16  9:26                                         ` Takenori Nagano
2007-08-16  9:45                                         ` Bernhard Walle
2007-08-16  9:45                                           ` Bernhard Walle
2007-08-17 10:56                                         ` Vivek Goyal
2007-08-17 10:56                                           ` Vivek Goyal
2007-08-21  7:45                                           ` Takenori Nagano
2007-08-21  7:45                                             ` Takenori Nagano
2007-08-23  3:52                                             ` Vivek Goyal
2007-08-23  3:52                                               ` Vivek Goyal
2007-08-21 13:18                                           ` Jay Lan
2007-08-21 13:18                                             ` Jay Lan
2007-08-21 13:21                                             ` Bernhard Walle
2007-08-21 13:21                                               ` Bernhard Walle
2007-08-23  3:56                                             ` Vivek Goyal
2007-08-23  3:56                                               ` Vivek Goyal
2007-08-23 17:34                                               ` Jay Lan
2007-08-23 17:34                                                 ` Jay Lan
2007-10-04 11:30                                                 ` Takenori Nagano

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