All of lore.kernel.org
 help / color / mirror / Atom feed
From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
	Dmitry Safonov <dima@arista.com>,
	linux-kernel@vger.kernel.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jiri Slaby <jslaby@suse.com>,
	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Subject: Re: [RFC] printk/sysrq: Don't play with console_loglevel
Date: Wed, 12 Jun 2019 17:36:43 +0900	[thread overview]
Message-ID: <20190612083643.GA7722@jagdpanzerIV> (raw)
In-Reply-To: <20190606071039.txqczrjlntrljlrx@pathway.suse.cz>

On (06/06/19 09:10), Petr Mladek wrote:
> > > > > > Provide KERN_UNSUPPRESSED printk() annotation for such legacy places.
> > > > > > Make sysrq print the headers unsuppressed instead of changing
> > > > > > console_loglevel.
> > > 
> > > I like this idea. console_loglevel is temporary manipulated only
> > > when some messages should or should never appear on the console.
> > > Storing this information in the message flags would help
> > > to solve all the related races.
> > 
> > I don't really like the whole system-wide console_loglevel manipulation
> > thing,
> 
> Just to be sure. I wanted to say that I like the idea with
> KERN_UNSUPRESSED. So, I think that we are on the same page.

I understand. All I wanted to say is that KERN_UNSUPRESSED is
per-message, while the most interesting (and actually broken)
cases, IMHO, are per-context, IOW things like this one

	console_loglevel = NEW
	foo()
	  dump_stack()
	     printk
	     ...
	     printk
	console_loglevel = OLD

KERN_UNSUPRESSED does not help here. We probably can't convert
dump_stack() to KERN_UNSUPRESSED.

[..]
> Now, KERN_EMERG might alarm some monitor of console output. It might
> trigger unwanted reaction (forced reboot?) of the monitoring system
> even when sysrq was not called in emergency situation.
> 
> I am sure that we need to care about such monitors. I have to
> think more about it.

Sure.

	-ss

  reply	other threads:[~2019-06-12  8:36 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-28  0:24 [RFC] printk/sysrq: Don't play with console_loglevel Dmitry Safonov
2019-05-28  3:21 ` Tetsuo Handa
2019-05-28  4:22   ` Sergey Senozhatsky
2019-05-28  8:02     ` Tetsuo Handa
2019-05-28  8:51       ` Sergey Senozhatsky
2019-05-28 10:15         ` Tetsuo Handa
2019-05-28 13:49           ` Petr Mladek
2019-06-07 17:09           ` Pavel Machek
2019-06-08  2:45             ` Tetsuo Handa
2019-06-11 15:10               ` Petr Mladek
2019-06-12 10:06                 ` Tetsuo Handa
2019-05-28  4:15 ` Sergey Senozhatsky
2019-05-28  4:46   ` Sergey Senozhatsky
2019-05-28 13:42     ` Petr Mladek
2019-05-28 14:21       ` Tetsuo Handa
2019-05-28 15:03         ` Petr Mladek
2019-05-28 15:21           ` Tetsuo Handa
2019-05-28 15:58             ` Dmitry Safonov
2019-05-31 14:11       ` Tetsuo Handa
2019-06-02  6:13         ` [RFC] printk: Introduce per context console loglevel Tetsuo Handa
2019-06-02  6:13           ` Tetsuo Handa
2019-06-06  7:59           ` Petr Mladek
2019-06-06  7:59             ` Petr Mladek
2019-06-03  6:51       ` [RFC] printk/sysrq: Don't play with console_loglevel Sergey Senozhatsky
2019-06-06  7:10         ` Petr Mladek
2019-06-12  8:36           ` Sergey Senozhatsky [this message]
2019-06-12 12:00             ` Petr Mladek
2019-06-12 14:47               ` Dmitry Safonov

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=20190612083643.GA7722@jagdpanzerIV \
    --to=sergey.senozhatsky.work@gmail.com \
    --cc=dima@arista.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=jslaby@suse.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=penguin-kernel@i-love.sakura.ne.jp \
    --cc=pmladek@suse.com \
    --cc=rostedt@goodmis.org \
    --cc=sergey.senozhatsky@gmail.com \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.