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From: "H. Peter Anvin" <hpa@linux.intel.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Dave Jones <davej@redhat.com>,
	Linux Kernel <linux-kernel@vger.kernel.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Ingo Molnar <mingo@redhat.com>, Andi Kleen <ak@linux.intel.com>
Subject: Re: BUG - function tracing with breakpoints
Date: Fri, 25 May 2012 10:40:49 -0700	[thread overview]
Message-ID: <4FBFC421.3020901@linux.intel.com> (raw)
In-Reply-To: <1337959746.13348.264.camel@gandalf.stny.rr.com>

On 05/25/2012 08:29 AM, Steven Rostedt wrote:
> 
> This would make sense for this bug, as if modifying_ftrace_code was not
> seen by other CPUs, it wouldn't go into the ftrace_int3_handler() path.
> That would cause this issue. But the bug remains after the smp_mb()'s
> were put in place. Although it behaves a little differently not. Maybe
> there's something else I missed?
> 

Perhaps you should make the modifying_ftrace_code modification atomic...
it seems odd to have it not be atomic when it is clearly accessed across
CPUs that way.

	-hpa



  reply	other threads:[~2012-05-25 17:40 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-05-24 16:01 tracing ring_buffer_resize oops Dave Jones
2012-05-24 16:19 ` Steven Rostedt
2012-05-24 17:22   ` Dave Jones
2012-05-24 17:35     ` Steven Rostedt
2012-05-24 18:47       ` Dave Jones
2012-05-24 18:54         ` Steven Rostedt
2012-05-24 19:11           ` Dave Jones
2012-05-24 19:24             ` Steven Rostedt
2012-05-24 20:05               ` Dave Jones
2012-05-24 20:18                 ` Steven Rostedt
2012-05-24 20:33                   ` Steven Rostedt
2012-05-24 21:15                     ` Dave Jones
2012-05-24 21:25                       ` Steven Rostedt
2012-05-24 22:49                 ` Steven Rostedt
2012-05-24 22:57                   ` Dave Jones
2012-05-24 23:40     ` Steven Rostedt
2012-05-24 23:53       ` H. Peter Anvin
2012-05-25  1:32         ` Steven Rostedt
2012-05-25  1:39         ` Steven Rostedt
2012-05-25  1:41           ` Steven Rostedt
2012-05-25 14:31             ` BUG - function tracing with breakpoints (was: Re: tracing ring_buffer_resize oops.) Steven Rostedt
2012-05-25 15:29               ` Steven Rostedt
2012-05-25 17:40                 ` H. Peter Anvin [this message]
2012-05-25 18:46                   ` BUG - function tracing with breakpoints Steven Rostedt
2012-05-25 20:51                     ` Steven Rostedt
2012-05-26  1:36                       ` Steven Rostedt
2012-05-29 11:37                       ` Steven Rostedt
2012-05-29 13:26                         ` Steven Rostedt
2012-05-25  0:14       ` tracing ring_buffer_resize oops Andi Kleen
2012-05-25  1:31         ` Steven Rostedt

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