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Date: Sat, 1 Apr 2017 09:04:50 +0900
From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
To: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>, Jan Kara <jack@suse.cz>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Peter Zijlstra <peterz@infradead.org>,
        "Rafael J . Wysocki" <rjw@rjwysocki.net>,
        Eric Biederman <ebiederm@xmission.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiri Slaby <jslaby@suse.com>, Pavel Machek <pavel@ucw.cz>,
        Len Brown <len.brown@intel.com>, linux-kernel@vger.kernel.org,
        Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Subject: Re: [RFC][PATCHv2 5/8] sysrq: switch to printk.emergency mode in
 unsafe places
Message-ID: <20170401000450.GB478@tigerII.localdomain>
References: <20170329092511.3958-1-sergey.senozhatsky@gmail.com>
 <20170329092511.3958-6-sergey.senozhatsky@gmail.com>
 <20170331153757.GA29537@pathway.suse.cz>
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Hello,

On (03/31/17 17:37), Petr Mladek wrote:
> On Wed 2017-03-29 18:25:08, Sergey Senozhatsky wrote:
> > It's not always possible/safe to wake_up() printk kernel
> > thread from sysrq (theoretically). Thus we better switch
> > printk() to emergency mode in some of the sysrq handlers,
> > which allows us to immediately flush pending kernel message
> > to the console.
> >
> > Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
> > Suggested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> 
> It looks like a decent selection. It is pity that some of
> them might produce rather long output and theoretically
> cause a softlookup. But I do not know about a better solution
> at the moment. In each case, it will not be worse than before
> this patchset.

thanks.

this patch will be replaced with a more 'generic' one, which
I posted in reply yo Ye Xiaolong's report.

	-ss