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<p>I am sure you guys will do regular performance runs on different versions of LTTng, but I couldn't find any links to the latest results. I was trying to find the cost of a tracepoint() recording one integer. On <span style="font-size: 12pt;">CPU Intel Xeon E5-2680
v2 @ 2.80GHz</span><span style="font-size: 12pt;">, running Linux </span><span style="font-size: 12pt;">3.6.11</span><span style="font-size: 12pt;"> and lttng 2.4.1, I am getting about 927 cycles (</span><span style="font-size: 12pt;">9270692144 cycles
for 10000000</span><span style="font-size: 12pt;"> iterations</span><span style="font-size: 12pt;">)</span><span style="font-size: 12pt;">. This seems to be lot higher than
</span><span style="font-size: 12pt;">the documented results </span><span style="font-size: 12pt;">. In the paper </span><a href="https://lttng.org/files/papers/desnoyers.pdf" style="font-size: 12pt;">https://lttng.org/files/papers/desnoyers.pdf</a><span style="font-size: 12pt;">
the av</span><span style="font-size: 12pt;">erage </span><span style="font-size: 12pt;">cost of tracepoin</span><span style="font-size: 12pt;">t()</span><span style="font-size: 12pt;"> w</span><span style="font-size: 12pt;">ith older </span><span style="font-size: 12pt;">ltt-usertrace-fast
tracepoint is 297 cycles. Another link </span><a href="http://lttng.org/files/thesis/desnoyers-thesis-defense-2009-12-e1.pdf" style="font-size: 12pt;"></a><a href="http://lttng.org/files/thesis/desnoyers-thesis-defense-2009-12-e1.pdf" style="font-size: 12pt;">http://lttng.org/files/thesis/desnoyers-thesis-defense-2009-12-e1.pdf</a><span style="font-size: 12pt;">
says cache hot tracepoint()</span><span style="font-size: 12pt;"> cost is 238 cycles.</span></p>
<p><span style="font-size: 12pt;"><br>
</span></p>
<p><span style="font-size: 12pt;">It appears that in spite of better cpu, and newer version of lttng and kernel I am seeing higher cost. Am I missing something here? Do I need to enable certain features of kernel/cpu ?</span></p>
<p><span style="font-size: 12pt;"><br>
</span></p>
<p><span style="font-size: 12pt;">VBabu</span></p>
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