Messages in this thread | | | Date | Fri, 15 Sep 2006 23:32:13 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH 0/11] LTTng-core (basic tracing infrastructure) 0.5.108 |
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* Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> wrote:
> * Ingo Molnar (mingo@elte.hu) wrote: > > sorry, but i disagree. There _is_ a solution that is superior in every > > aspect: kprobes + SystemTap. (or any other equivalent dynamic tracer) > > > > I am sorry to have to repeat myself, but this is not true for heavy > loads.
djprobes?
> > > At this point you've been rather uncompromising [...] > > > > yes, i'm rather uncompromising when i sense attempts to push inferior > > concepts into the core kernel _when_ a better concept exists here and > > today. Especially if the concept being pushed adds more than 350 > > tracepoints that expose something to user-space that amounts to a > > complex external API, which tracepoints we have little chance of ever > > getting rid of under a static tracing concept. > > > From an earlier email from Tim bird : > > "I still think that this is off-topic for the patch posted. I think > we should debate the implementation of tracepoints/markers when > someone posts a patch for some. I think it's rather scurrilous to > complain about code NOT submitted. Ingo has even mis-characterized > the not-submitted instrumentation patch, by saying it has 350 > tracepoints when it has no such thing. I counted 58 for one > architecture (with only 8 being arch-specific)."
i missed that (way too many mails in this thread).
Here is how i counted them:
$ grep "\<trace_.*(" * | wc -l 359
some of those are not true tracepoints, but there's at least this many of them:
$ grep "\<trace_.*(" *instrumentation* | wc -l 235
so the real number is somewhere between.
patch-2.6.17-lttng-0.5.108-instrumentation-arm.diff patch-2.6.17-lttng-0.5.108-instrumentation.diff patch-2.6.17-lttng-0.5.108-instrumentation-i386.diff patch-2.6.17-lttng-0.5.108-instrumentation-mips.diff patch-2.6.17-lttng-0.5.108-instrumentation-powerpc.diff patch-2.6.17-lttng-0.5.108-instrumentation-ppc.diff patch-2.6.17-lttng-0.5.108-instrumentation-s390.diff patch-2.6.17-lttng-0.5.108-instrumentation-sh.diff patch-2.6.17-lttng-0.5.108-instrumentation-x86_64.diff
when judging kernel maintainance overhead, the sum of all patches matters. And i considered all the other patches too (the ones that add actual tracepoints) that will come after the currently offered ones, not just the ones you submitted to lkml.
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