|| ||Theodore Tso <tytso-AT-MIT.EDU> |
|| ||Frederic Weisbecker <fweisbec-AT-gmail.com> |
|| ||Re: [PATCH 0/18] Allow different tracers to be compiled independently |
|| ||Mon, 22 Mar 2010 23:34:33 -0400|
|| ||Jan Kara <jack-AT-suse.cz>, Steven Rostedt <rostedt-AT-goodmis.org>,
Ingo Molnar <mingo-AT-elte.hu>,
Thomas Gleixner <tglx-AT-linutronix.de>,
Li Zefan <lizf-AT-cn.fujitsu.com>,
Peter Zijlstra <a.p.zijlstra-AT-chello.nl>,
Masami Hiramatsu <mhiramat-AT-redhat.com>,
Mathieu Desnoyers <mathieu.desnoyers-AT-efficios.com>,
|| ||Article, Thread
On Mar 22, 2010, at 9:04 PM, Frederic Weisbecker wrote:
> I don't know. Yeah this first looks like a good idea but once
> CONFIG_EVENT_TRACING is enabled, each tracepoint is a lightweight
> thing and induce a tiny overhead, probably hard to notice, and
> this is going to be even more the case after the jmp label
> optimization patches.
> I liked the fact we had a general tracing kernel once the above
> config is selected. And we don't bother telling people that to
> use tool X you need CONFIG_EVENT_Y, and you need to rebuild your
> kernel, etc...
Indeed, a lot of the value of tracepoints goes away if people are compiling kernels without them
and we need to get a special "tracing kernel" installed before we can debug a problem.
So I'd hope we can do the necessary optimization work so people don't feel it's necessary to enable
or disable tracepoints by subsystem....
to post comments)