Messages in this thread | | | Date | Thu, 20 May 2010 13:42:18 +0200 | From | Ingo Molnar <> | Subject | Re: [RFD] Future tracing/instrumentation directions |
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* Thomas Gleixner <tglx@linutronix.de> wrote:
> On Thu, 20 May 2010, Frederic Weisbecker wrote: > > On Thu, May 20, 2010 at 11:31:31AM +0200, Ingo Molnar wrote: > > > - [ While it's still a long way off, if this trend continues > > > we eventually might even be able to get rid of the > > > /debug/tracing/ temporary debug API and get rid of > > > the ugly in-kernel pretty-printing bits. This is > > > good: it may make Andrew very happy for a change ;-) > > > > > > The main detail here to be careful of is that lots of > > > people are fond of the simplicity of the > > > /debug/tracing/ debug UI, so when we replace it we > > > want to do it by keeping that simple workflow (or > > > best by making it even simpler). I have a few ideas > > > how to do this. > > > > How? We can emulate the /debug/tracing result with something > > like perf trace, still that won't replace the immediate > > availability of the result of any trace, which makes it > > valuable for any simplest workflows. > > I'm a bit torn about this. I really like the availability of the ascii > interface, but if we can come up with a very basic trace binary tool > which can be built for deep embedded w/o requiring the world and some > more libs to be available, then I might give up my resistance. Ideally > it should be done so it can be easily integrated into busybox. > > I don't care whether I do > > echo 1 >/debug/..../XXX/enable > cat /debug/tracing/trace > > or > > perfmini trace enable XXX > perfmini trace dump
My suggestion for that flow is even shorter:
trace --enable XXX trace
Plus:
trace --list trace --enable trace --disable
> as long as the tool is built in a way that it does not > need updates when we add trace points or other > functionality to the kernel.
Yeah, most definitely. The sysfs event_source class will ensure that whatever (new) events are available propagate through the tool and are available to it.
Thanks,
Ingo
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