Messages in this thread | | | Date | Wed, 16 Jan 2008 12:45:14 -0800 | From | Tim Bird <> | Subject | Re: [RFC PATCH 16/22 -v2] add get_monotonic_cycles |
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Mathieu Desnoyers wrote: > If LTTng is already ported to your specific kernel, the learning-curve > is not big at all. Here is what the latency_tracer over LTTng guide > could look like : > > Well, once you have LTTng in your kernel and have compiled and installed > the ltt-control and lttv packages (configure, make, make install), all > that would be needed is : > > (there may be some bits in the QUICKSTART GUIDE on > http://ltt.polymtl.ca, like adding the debugfs mount to fstab and make sure > the LTTng modules are loaded) > > #arm all the markers > ltt-armall > #start lttng tracing > lttctl -n test -t /tmp/trace1 -d -l /mnt/debugfs/ltt > > -> start latency tracer > -> stop latency tracer > -> trigger latency tracer dump > > While the tracing is active, trigger the condition... > > (rince, repeat, can handle multiple latency tracer dumps) > > #stop lttng tracing > lttctl -n test -R > #disarm all markers > ltt-disarmall > > You can easily test the trace with : > lttv -m textDump -t /tmp/trace1 > > Your users would issue something like : > > lttv -m latencytracerDump -t /tmp/trace1
No offense, but this is still quite a bit harder than:
echo 1 >/proc/something ... wait a bit ... cat /proc/something
(substitute /sys or /debugfs where appropriate)
Having to compile something (besides the kernel) for the target is sometimes a major hassle. I avoided it completely with KFT. -- Tim
============================= Tim Bird Architecture Group Chair, CE Linux Forum Senior Staff Engineer, Sony Corporation of America =============================
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