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Date: Tue, 23 Jun 2009 19:40:00 -0000
From: Ingo Molnar <mingo@elte.hu>
To: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>, 	lkml <linux-kernel@vger.kernel.org>, 	"H. Peter Anvin" <hpa@zytor.com>, 	Frederic Weisbecker <fweisbec@gmail.com>, 	Jim Keniston <jkenisto@us.ibm.com>, 	Srikar Dronamraju <srikar@linux.vnet.ibm.com>, 	Christoph Hellwig <hch@infradead.org>, 	Steven Rostedt <rostedt@goodmis.org>, 	Anders Kaseorg <andersk@ksplice.com>, 	Tim Abbott <tabbott@ksplice.com>, 	systemtap <systemtap@sources.redhat.com>, 	DLE <dle-develop@lists.sourceforge.net>
Subject: Re: [RFC][ PATCH -tip v2 0/7] kprobes: Kprobes jump optimization 	support
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* Masami Hiramatsu <mhiramat@redhat.com> wrote:

> Ingo Molnar wrote:
> > * Masami Hiramatsu <mhiramat@redhat.com> wrote:
> > 
> >> o Usage
> >>  Set CONFIG_OPTPROBES=y when building a kernel, then all *probes will be
> >> optimized if possible.
> > 
> > Should be default-y if KPROBES is enabled. I.e. we really only want 
> > to disable it to debug potential issues.
> 
> Sure, thanks!

Plus i'd suggest a runtime control (a sysctl) as well - if it's not 
too intrusive. Since this is an optional speedup feature, distros 
can have this enabled and if there's some problem with it then it 
can still be disabled in sysctl.conf, without having to rebuild the 
kernel.

	Ingo