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From: Peter Zijlstra <peterz@infradead.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@elte.hu>,
	Andrew Morton <akpm@linux-foundation.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
	"H. Peter Anvin" <hpa@zytor.com>, Dave Jones <davej@redhat.com>,
	Andi Kleen <ak@linux.intel.com>
Subject: Re: [PATCH 1/5] ftrace: Synchronize variable setting with breakpoints
Date: Thu, 31 May 2012 19:40:29 +0200	[thread overview]
Message-ID: <1338486029.28384.93.camel@twins> (raw)
In-Reply-To: <1338473302.13348.336.camel@gandalf.stny.rr.com>

On Thu, 2012-05-31 at 10:08 -0400, Steven Rostedt wrote:
> > Also, why does this stuff live in ftrace? I always thought you were
> > going to replace text_poke() so everybody that uses cross-modifying code
> > could profit?
> 
> I discussed this with Masami at Collaboration Summit. The two are
> similar but also very different. But we want to start merging the two
> together where it makes sense. 

Argh,. I so disagree. You're doing it backwards.

First you merge whatever is there, regardless of who came first.

Then, when everybody doing text modification is using the same
interface, do a second implementation using a Kconfig knob. If the scary
new one breaks, no sweat, flip the config. If its proven stable, kill
off the old one.

I really don't see why ftrace would be special here.. if you have all
text_poke() users use the magic new way you'll have more coverage and
better chances of hitting any snags if there are any.



  parent reply	other threads:[~2012-05-31 17:40 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-05-31  1:28 [PATCH 0/5] [GIT PULL] ftrace: Fix bug with function tracing and lockdep Steven Rostedt
2012-05-31  1:28 ` [PATCH 1/5] ftrace: Synchronize variable setting with breakpoints Steven Rostedt
2012-05-31 11:06   ` Peter Zijlstra
2012-05-31 14:08     ` Steven Rostedt
2012-05-31 15:16       ` Masami Hiramatsu
2012-05-31 15:29         ` Steven Rostedt
2012-05-31 17:28       ` Peter Zijlstra
2012-05-31 18:42         ` Steven Rostedt
2012-05-31 17:40       ` Peter Zijlstra [this message]
2012-05-31 17:44         ` Peter Zijlstra
2012-05-31 17:53         ` Steven Rostedt
2012-05-31 18:03           ` Peter Zijlstra
2012-05-31 18:50             ` Steven Rostedt
2012-05-31 19:06               ` Peter Zijlstra
2012-05-31 19:55                 ` Mathieu Desnoyers
2012-05-31 20:10                   ` Steven Rostedt
2012-05-31 20:26                     ` Peter Zijlstra
2012-05-31 20:37                       ` Steven Rostedt
2012-05-31 20:40                         ` Steven Rostedt
2012-05-31 20:40                         ` Peter Zijlstra
2012-05-31 20:49                           ` Steven Rostedt
2012-06-01  4:53                             ` Masami Hiramatsu
2012-06-01 11:37                               ` Steven Rostedt
2012-06-01 12:52                                 ` Masami Hiramatsu
2012-06-01  0:45                       ` Arnaldo Carvalho de Melo
2012-05-31  1:28 ` [PATCH 2/5] ftrace: Use breakpoint method to update ftrace caller Steven Rostedt
2012-05-31 11:18   ` Peter Zijlstra
2012-05-31 14:19     ` Steven Rostedt
2012-05-31  1:28 ` [PATCH 3/5] x86: Reset the debug_stack update counter Steven Rostedt
2012-05-31 19:19   ` H. Peter Anvin
2012-05-31 19:26     ` Steven Rostedt
2012-05-31  1:28 ` [PATCH 4/5] x86: Allow nesting of the debug stack IDT setting Steven Rostedt
2012-05-31 18:44   ` H. Peter Anvin
2012-05-31 18:58   ` H. Peter Anvin
2012-05-31 19:25     ` Steven Rostedt
2012-05-31 19:27       ` H. Peter Anvin
2012-05-31 20:00         ` Steven Rostedt
2012-05-31 20:17           ` H. Peter Anvin
2012-05-31 20:35             ` Steven Rostedt
2012-05-31 20:39               ` H. Peter Anvin
2012-05-31 20:56                 ` Steven Rostedt
2012-05-31 21:09                   ` H. Peter Anvin
2012-05-31 21:37                     ` Steven Rostedt
2012-05-31 21:38                       ` Steven Rostedt
2012-06-01  2:30       ` Steven Rostedt
2012-05-31  1:28 ` [PATCH 5/5] ftrace/x86: Do not change stacks in DEBUG when calling lockdep Steven Rostedt
2012-05-31  2:13 ` [PATCH 0/5] (for 3.5)[GIT PULL] ftrace: Fix bug with function tracing and lockdep Steven Rostedt

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