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Date: Sat, 25 Mar 2017 11:59:07 +0100 (CET)
From: Sebastian Ott <sebott@linux.vnet.ibm.com>
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To: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
cc: Petr Mladek <pmladek@suse.com>, Steven Rostedt <rostedt@goodmis.org>,
        Andrew Morton <akpm@linux-foundation.org>,
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        Heiko Carstens <heiko.carstens@de.ibm.com>,
        Martin Schwidefsky <schwidefsky@de.ibm.com>,
        linux-kernel@vger.kernel.org,
        Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Subject: Re: lockdep warning: console vs. mem hotplug
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On Sat, 25 Mar 2017, Sergey Senozhatsky wrote:

> On (03/21/17 13:44), Sergey Senozhatsky wrote:
> [..]
> > so we probably can
> > 
> > 
> > 1) move pr_info() out of zone->lock in __offline_isolated_pages().
> >    meh...
> > 
> > 
> > 2) switch to printk_deferred() in __offline_isolated_pages().
> >    meh.. there might a bunch of other printks done from under zone->lock.
> > 
> > 
> > 3) move add_timer() out of sclp_con_lock console in sclp_console_write().
> >    well, there can be other consoles that do something similar.
> > 
> > 
> > 4) ... something smart.
> 
> 
> Sebastian, does this change make lockdep happy?
> 
> it removes console drivers from the __offline_isolated_pages(). not the
> best solution I can think of, but the simplest one.

It does. No complaint from lockdep.