From: Andi Kleen <andi@firstfloor.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Olsa <jolsa@redhat.com>,
Steven Rostedt <rostedt@goodmis.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
linux-kernel@vger.kernel.org, Ingo Molnar <mingo@kernel.org>,
Josh Triplett <josh@joshtriplett.org>,
Andi Kleen <andi@firstfloor.org>,
Jan Stancek <jstancek@redhat.com>
Subject: Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage!
Date: Mon, 21 Nov 2016 09:06:13 -0800 [thread overview]
Message-ID: <20161121170612.GT26852@two.firstfloor.org> (raw)
In-Reply-To: <20161121092850.GF3102@twins.programming.kicks-ass.net>
> > it got away with attached change.. but this rcu logic
> > is far beyond me, so it's just wild guess.. ;-)
>
> I think I prefer something like the below, that only annotates the one
> RDMSR in question, instead of all of them.
It would be far better to just fix trace points that they always work.
This whole thing is a travesty: we have tens of thousands of lines of code in
ftrace to support tracing in NMIs, but then "debug features"[1] like
this come around and make trace points unusable for far more code than
just the NMI handlers.
-Andi
[1] unclear what they actually "debug" here.
next prev parent reply other threads:[~2016-11-21 17:06 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-21 0:53 [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Jiri Olsa
2016-11-21 9:02 ` Paul E. McKenney
2016-11-21 9:43 ` Peter Zijlstra
2016-11-21 11:00 ` Paul E. McKenney
2016-11-21 9:28 ` Peter Zijlstra
2016-11-21 9:34 ` Jiri Olsa
2016-11-21 9:42 ` Peter Zijlstra
2016-11-21 11:22 ` Jiri Olsa
2016-11-21 11:31 ` Peter Zijlstra
2016-11-21 12:49 ` Jiri Olsa
2016-11-21 12:58 ` Peter Zijlstra
2016-11-21 14:15 ` Steven Rostedt
2016-11-21 14:37 ` Peter Zijlstra
2016-11-21 15:35 ` Borislav Petkov
2016-11-21 15:41 ` Peter Zijlstra
2016-11-21 16:06 ` Borislav Petkov
2016-11-29 13:16 ` Borislav Petkov
2016-11-29 13:59 ` Thomas Gleixner
2016-11-30 8:48 ` Borislav Petkov
2016-11-30 8:54 ` Thomas Gleixner
2016-11-30 9:07 ` Borislav Petkov
2016-11-30 9:14 ` Thomas Gleixner
2016-11-29 14:04 ` Jiri Olsa
2016-11-21 14:20 ` Steven Rostedt
2016-11-21 17:06 ` Andi Kleen [this message]
2016-11-21 17:18 ` Peter Zijlstra
2016-11-21 17:45 ` Andi Kleen
2016-11-21 18:01 ` Steven Rostedt
2016-11-21 18:06 ` Andi Kleen
2016-11-21 18:22 ` Steven Rostedt
2016-11-21 18:37 ` Andi Kleen
2016-11-21 19:06 ` Steven Rostedt
2016-11-21 19:15 ` Steven Rostedt
2016-11-21 20:44 ` Andi Kleen
2016-11-22 8:19 ` Paul E. McKenney
2016-11-22 14:39 ` Steven Rostedt
2016-11-22 19:05 ` Andi Kleen
2016-11-24 2:06 ` Steven Rostedt
2016-11-28 21:48 ` Andi Kleen
2016-11-28 22:46 ` Steven Rostedt
2016-11-28 23:10 ` Andi Kleen
2016-11-21 17:55 ` Steven Rostedt
2016-11-21 18:24 ` Steven Rostedt
2016-11-21 20:12 ` Paul E. McKenney
2017-02-23 12:24 ` Jiri Olsa
2017-02-23 17:11 ` Andi Kleen
2017-02-23 17:28 ` Peter Zijlstra
2017-02-23 17:56 ` Borislav Petkov
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