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From: Miroslav Benes <mbenes@suse.cz>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Ingo Molnar <mingo@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH v2] tracing: Make sure RCU is watching before calling a stack trace
Date: Thu, 18 May 2017 15:48:55 +0200 (CEST)	[thread overview]
Message-ID: <alpine.LSU.2.20.1705181547170.31625@pobox.suse.cz> (raw)
In-Reply-To: <20170518093809.13428efa@gandalf.local.home>

On Thu, 18 May 2017, Steven Rostedt wrote:

> 
> From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
> 
> As stack tracing now requires "rcu watching", force RCU to be watching when
> recording a stack trace.
> 
> Link: http://lkml.kernel.org/r/20170512172449.879684501@goodmis.org
> 
> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
> ---
> 
> Changes since v1:
> 
>    My testing discovered that the stack trace can be called with
>    interrupts enabled, which is a no no to have when calling
>    rcu_irq_enter(). When interrupts are enabled, as with being in an
>    NMI, RCU will also be watching.

Would rcu_irq_enter_irqson() help then? This is what Petr used in a live 
patching handler.

Your solution works too, of course. Just asking if I am not missing 
something.

Thanks,
Miroslav

  reply	other threads:[~2017-05-18 13:49 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-18 13:38 Steven Rostedt
2017-05-18 13:48 ` Miroslav Benes [this message]
2017-05-18 14:04   ` Steven Rostedt
2017-05-18 18:18     ` Miroslav Benes
2017-05-18 14:50 ` Steven Rostedt
2017-05-18 15:47 ` Paul E. McKenney
2017-05-18 16:39   ` Steven Rostedt
2017-05-18 18:45     ` Paul E. McKenney
2017-05-18 19:30       ` Steven Rostedt
2017-05-18 19:50         ` Paul E. McKenney

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