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From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
To: Daniel Walker <dwalker@mvista.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
	LKML <linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@elte.hu>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Christoph Hellwig <hch@infradead.org>,
	Gregory Haskins <ghaskins@novell.com>,
	Arnaldo Carvalho de Melo <acme@ghostprotocols.net>,
	Thomas Gleixner <tglx@linutronix.de>,
	Tim Bird <tim.bird@am.sony.com>, Sam Ravnborg <sam@ravnborg.org>,
	"Frank Ch. Eigler" <fche@redhat.com>,
	Jan Kiszka <jan.kiszka@siemens.com>,
	John Stultz <johnstul@us.ibm.com>,
	Arjan van de Ven <arjan@infradead.org>,
	Steven Rostedt <srostedt@redhat.com>
Subject: Re: [PATCH 01/20 -v5] printk - dont wakeup klogd with interrupts disabled
Date: Wed, 23 Jan 2008 12:25:09 -0500	[thread overview]
Message-ID: <20080123172509.GC22229@Krystal> (raw)
In-Reply-To: <1201107978.13596.16.camel@imap.mvista.com>

* Daniel Walker (dwalker@mvista.com) wrote:
> 
> On Wed, 2008-01-23 at 11:02 -0500, Steven Rostedt wrote:
> 
> > +	if (!irqs_disabled() && wake_klogd)
> >  		wake_up_klogd();
> 
> This causes a regression .. When printk is called during an OOPS in
> kernels without this change then the OOPS will get logged, since the
> logging process (klogd) is woken to handle the messages.. If you apply
> this change klogd doesn't wakeup, and hence doesn't log the oops.. So if
> you remove the wakeup here you have to add it someplace else to maintain
> the logging ..
> 
> (I'm not theorizing here, I have defects logged against this specific
> piece of code..)
> 

Can we change this for :
if (!(irqs_disabled() && !oops_in_progress) && wake_klogd)
  wake_up_klogd();

?

(totally untested)

> Daniel
> 

-- 
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68

  reply	other threads:[~2008-01-23 17:34 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-01-23 16:02 [PATCH 00/20 -v5] mcount and latency tracing utility -v5 Steven Rostedt
2008-01-23 16:02 ` [PATCH 01/20 -v5] printk - dont wakeup klogd with interrupts disabled Steven Rostedt
2008-01-23 17:06   ` Daniel Walker
2008-01-23 17:25     ` Mathieu Desnoyers [this message]
2008-01-23 17:49       ` Tim Bird
2008-01-24 10:35       ` Pavel Machek
2008-01-23 17:27     ` Steven Rostedt
2008-01-23 17:32       ` Mathieu Desnoyers
2008-01-23 17:43       ` Daniel Walker
2008-01-23 18:18         ` Steven Rostedt
2008-01-23 18:28           ` Daniel Walker
2008-01-23 18:43             ` Steven Rostedt
2008-01-23 18:50               ` Daniel Walker
2008-01-23 19:59                 ` Daniel Walker
2008-01-24 22:42           ` [PATCH] defer printks in irqs Tim Bird
2008-01-24 22:48             ` Peter Zijlstra
2008-01-24 23:23               ` Tim Bird
2008-01-27  6:01                 ` Andrew Morton
2008-01-28 21:14                   ` Tim Bird
2008-01-24 10:36       ` [PATCH 01/20 -v5] printk - dont wakeup klogd with interrupts disabled Pavel Machek
2008-01-23 16:02 ` [PATCH 02/20 -v5] Add basic support for gcc profiler instrumentation Steven Rostedt
2008-01-23 16:02 ` [PATCH 03/20 -v5] Annotate core code that should not be traced Steven Rostedt
2008-01-23 16:02 ` [PATCH 04/20 -v5] x86_64: notrace annotations Steven Rostedt
2008-01-23 16:02 ` [PATCH 05/20 -v5] add notrace annotations to vsyscall Steven Rostedt
2008-01-23 16:02 ` [PATCH 06/20 -v5] add notrace annotations for NMI routines Steven Rostedt
2008-01-23 21:31   ` Mathieu Desnoyers
2008-01-23 21:58     ` Steven Rostedt
2008-01-26  5:25     ` Steven Rostedt
2008-01-28 11:51       ` Jan Kiszka
2008-01-28 12:15         ` Steven Rostedt
2008-01-23 16:02 ` [PATCH 07/20 -v5] handle accurate time keeping over long delays Steven Rostedt
2008-01-23 16:02 ` [PATCH 08/20 -v5] initialize the clock source to jiffies clock Steven Rostedt
2008-01-23 16:40   ` Tim Bird
2008-01-23 16:02 ` [PATCH 09/20 -v5] add get_monotonic_cycles Steven Rostedt
2008-01-23 16:02 ` [PATCH 10/20 -v5] add notrace annotations to timing events Steven Rostedt
2008-01-23 16:02 ` [PATCH 11/20 -v5] mcount based trace in the form of a header file library Steven Rostedt
2008-01-23 16:02 ` [PATCH 12/20 -v5] Add context switch marker to sched.c Steven Rostedt
2008-01-23 16:02 ` [PATCH 13/20 -v5] Make the task State char-string visible to all Steven Rostedt
2008-01-23 16:02 ` [PATCH 14/20 -v5] Add tracing of context switches Steven Rostedt
2008-01-23 16:02 ` [PATCH 15/20 -v5] Generic command line storage Steven Rostedt
2008-01-23 16:02 ` [PATCH 16/20 -v5] trace generic call to schedule switch Steven Rostedt
2008-01-23 16:02 ` [PATCH 17/20 -v5] Add marker in try_to_wake_up Steven Rostedt
2008-01-23 16:02 ` [PATCH 18/20 -v5] mcount tracer for wakeup latency timings Steven Rostedt
2008-01-23 16:02 ` [PATCH 19/20 -v5] Trace irq disabled critical timings Steven Rostedt
2008-01-23 16:53   ` Steven Rostedt
2008-01-23 17:11     ` Steven Rostedt
2008-01-23 17:27       ` Frank Ch. Eigler
2008-01-23 17:45         ` Steven Rostedt
2008-01-23 17:54           ` Mathieu Desnoyers
2008-01-23 17:58         ` Peter Zijlstra
2008-01-23 18:25           ` Frank Ch. Eigler
2008-01-23 18:48             ` Steven Rostedt
2008-01-23 21:29           ` Mathieu Desnoyers
2008-01-23 16:02 ` [PATCH 20/20 -v5] trace preempt off " Steven Rostedt

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