System information

102 System Analysis and Tuning Guide
File Description
reset_pmds_count Number of times
pfm_reset_pmds() is called
set_switch_count Number of event set switches
set_switch_ns Number of nanoseconds spent in the
set switching rountine
Average cost of switching sets =
set_switch_ns /
set_switch_count
This might be useful to compare your metrics before and after the perfmon run. For
example, collect your data first:
for i in /sys/kernel/debug/perfmon/cpu0/*; do
echo "$i:"; cat $i
done >> pfmon-before.txt
Run your performance monitoring, maybe restrict it to a specific CPU:
pfmon --cpu-list=0 ...
Collect your data again:
for i in /sys/kernel/debug//perfmon/cpu0/*; do
echo "$i:"; cat $i
done >> pfmon-after.txt
Compare these two files:
diff -u pfmon-before.txt pfmon-after.txt
7.5 For More Information
This chapter only provides a short overview. Refer to the following links for more in-
formation:
http://perfmon2.sourceforge.net/
The project home page.
http://www.iop.org/EJ/arti
cle/1742-6596/119/4/042017/jpconf8_119_042017.pdf
A good overview as PDF.