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From: Steven Rostedt <rostedt@goodmis.org>
To: David Woodhouse <dwmw2@infradead.org>
Cc: ksummit-discuss@lists.linuxfoundation.org
Subject: Re: [Ksummit-discuss] [TECH TOPIC] asynchronous printk
Date: Wed, 27 Jul 2016 22:55:14 -0400	[thread overview]
Message-ID: <20160727225514.39968c3b@grimm.local.home> (raw)
In-Reply-To: <1469097402.120686.129.camel@infradead.org>

On Thu, 21 Jul 2016 11:36:42 +0100
David Woodhouse <dwmw2@infradead.org> wrote:


> A viable solution to fix this might be a 'synchronous' flag on the
> console itself — so I could boot with 'console=ttyS0,synchronous' and
> get a debuggable system again, Or maybe it would be simpler to have a
> system-wide control which makes all consoles synchronous, if that's
> easier. Either way, we do need the option, and we need it to apply to
> *all* output, not just KERN_EMERG messages.
> 

For these cases I use, earlyprintk=ttyS0,keep

;-)

Actually, the RT patch has a option to force all printk()s to be
earlyprintk directly. I have a separate patch that has a special
spinlock to keep SMP from stomping all over the output. It's special
because it locks per CPU, if an NMI comes in while the current context
has the lock and is printing, it will corrupt the buffer being printed,
but I don't care at that moment. If NMI is doing printks, its message
will be more important anyway.

-- Steve

  parent reply	other threads:[~2016-07-28  2:55 UTC|newest]

Thread overview: 60+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-19  3:47 Sergey Senozhatsky
2016-07-19  3:56 ` Viresh Kumar
2016-07-19  6:17 ` Hannes Reinecke
2016-07-19  6:49   ` Josh Triplett
2016-07-19  7:02     ` Hannes Reinecke
2016-07-19  7:11       ` Geert Uytterhoeven
2016-07-20  6:02         ` Jan Kara
2016-07-20 22:54       ` Josh Triplett
2016-07-21  0:46         ` Sergey Senozhatsky
2016-07-21  1:12           ` Josh Triplett
2016-07-19  7:33   ` Sergey Senozhatsky
2016-07-19  7:38     ` Hannes Reinecke
2016-07-19  7:46       ` Sergey Senozhatsky
2016-07-19  8:02         ` Hannes Reinecke
2016-07-19  8:23           ` Sergey Senozhatsky
2016-07-21 10:36           ` David Woodhouse
2016-07-21 12:31             ` Jan Kara
2016-07-28  2:55             ` Steven Rostedt [this message]
2016-07-20  6:09       ` Jan Kara
2016-07-19  7:46   ` Christian Borntraeger
2016-07-19  7:53     ` Christian Borntraeger
2016-07-19 13:55       ` Jan Kara
2016-07-28  2:59         ` Steven Rostedt
2016-07-28  4:12           ` Sergey Senozhatsky
2016-07-28 13:02             ` Steven Rostedt
2016-07-20  3:35   ` Wangnan (F)
2016-07-21  1:16     ` Andy Lutomirski
2016-07-21  1:52       ` Wangnan (F)
2016-07-21  5:59       ` Hannes Reinecke
2016-07-21 10:31         ` David Woodhouse
2016-07-21 11:19           ` Josh Triplett
2016-07-21 11:59             ` David Woodhouse
2016-07-21 14:21               ` Josh Triplett
2016-07-21 14:40                 ` David Woodhouse
2016-07-28  3:05                 ` Steven Rostedt
2016-08-02 11:59               ` Petr Mladek
2016-07-21 15:05           ` Andy Lutomirski
2016-07-26 14:40             ` David Woodhouse
2016-07-26 15:44               ` Benjamin Herrenschmidt
2016-07-26 21:00               ` Andy Lutomirski
2016-07-27  0:03                 ` David Woodhouse
2016-07-27  1:16                   ` Sergey Senozhatsky
2016-07-21 10:28       ` David Woodhouse
2016-07-19 14:45 ` James Bottomley
2016-07-19 14:55   ` Sergey Senozhatsky
2016-07-19 17:58     ` James Bottomley
2016-07-19 18:24       ` Viresh Kumar
2016-07-20  2:08       ` Sergey Senozhatsky
2016-07-20  6:14     ` Jan Kara
2016-09-21  4:41 ` Sergey Senozhatsky
2016-10-31  6:54   ` Sergey Senozhatsky
2016-10-31 13:56     ` Theodore Ts'o
2016-10-31 13:59       ` Jiri Kosina
2016-10-31 14:56       ` [Ksummit-discuss] [TECH TOPIC] printk considered harmful (was: [TECH TOPIC] asynchronous printk) Sergey Senozhatsky
2016-10-31 16:18         ` Theodore Ts'o
2016-10-31 18:21           ` Sergey Senozhatsky
2016-10-31 18:26             ` [Ksummit-discuss] [TECH TOPIC] printk considered harmful Hannes Reinecke
2016-10-31 20:28           ` [Ksummit-discuss] [TECH TOPIC] printk considered harmful (was: [TECH TOPIC] asynchronous printk) Jan Kara
2016-11-01 12:27             ` [Ksummit-discuss] [TECH TOPIC] printk considered harmful Hannes Reinecke
2016-11-01 17:50         ` [Ksummit-discuss] [TECH TOPIC] printk considered harmful (was: [TECH TOPIC] asynchronous printk) Sergey Senozhatsky

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