Not a big problem yet, but at some point we should look into this...
The normal perf_output-consuming loop we've been using is:
This wakes up as quickly as it can, and can consume noticeable CPU. I had to tune it for my cpuunclaimed tool:
while 1:
# allow some buffering by calling sleep(), to reduce the context switch
# rate and lower overhead.
try:
if not exiting:
sleep(wakeup_s)
except KeyboardInterrupt:
exiting = 1
b.kprobe_poll()
slept += wakeup_s
This ticket is to explore doing this for more tools. Should b.kprobe_poll() have a built-in sleep, that can be tuned? Eg, 100ms by default?
This is more practical now we have #997, and can increase the buffer size.