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Re: [RFC][ PATCH -tip v2 0/7] kprobes: Kprobes jump optimization support
- From: Ingo Molnar <mingo at elte dot hu>
- To: Masami Hiramatsu <mhiramat at redhat dot com>
- Cc: Ananth N Mavinakayanahalli <ananth at in dot ibm dot com>, lkml <linux-kernel at vger dot kernel dot org>, "H. Peter Anvin" <hpa at zytor dot com>, Frederic Weisbecker <fweisbec at gmail dot com>, Jim Keniston <jkenisto at us dot ibm dot com>, Srikar Dronamraju <srikar at linux dot vnet dot ibm dot com>, Christoph Hellwig <hch at infradead dot org>, Steven Rostedt <rostedt at goodmis dot org>, Anders Kaseorg <andersk at ksplice dot com>, Tim Abbott <tabbott at ksplice dot com>, systemtap <systemtap at sources dot redhat dot com>, DLE <dle-develop at lists dot sourceforge dot net>
- Date: Tue, 23 Jun 2009 21:40:09 +0200
- Subject: Re: [RFC][ PATCH -tip v2 0/7] kprobes: Kprobes jump optimization support
- References: <20090622212255.5384.53732.stgit@localhost.localdomain> <20090623114252.GB9497@elte.hu> <4A40E153.9030704@redhat.com>
* 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