linux-kernel - Re: [RFC][PATCH 0/3] x86/nmi: Print all cpu stacks from NMI safely

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Message-ID: <alpine.LNX.2.00.1406251200051.15939@pobox.suse.cz>
Date:	Wed, 25 Jun 2014 12:01:49 +0200 (CEST)
From:	Jiri Kosina <jkosina@...e.cz>
To:	Konstantin Khlebnikov <koct9i@...il.com>
cc:	Petr Mládek <pmladek@...e.cz>,
	Steven Rostedt <rostedt@...dmis.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Ingo Molnar <mingo@...nel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Michal Hocko <mhocko@...e.cz>, Jan Kara <jack@...e.cz>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Dave Anderson <anderson@...hat.com>
Subject: Re: [RFC][PATCH 0/3] x86/nmi: Print all cpu stacks from NMI safely

On Tue, 24 Jun 2014, Konstantin Khlebnikov wrote:

> Originally I thought that seizing all cpus one by one and printing from 
> the initiator is a best approach and I've started preparing arguments 
> against over-engineered printk...

By "seizing" I guess you mean sending IPI, right?

What do you do if you'd interrupt it in the middle of printk() in order 
not to deadlock by trying to take the buffer lock on the initiator CPU?

-- 
Jiri Kosina
SUSE Labs
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