Linux perf stat tool returns a null command counter. What am I missing here?

Question

I am trying to get some basic performance data on my new Galaxy S4 phone. I already compiled a custom kernel and managed to bring it to the device using Odin. These are the kernel modules associated with the primary tool that I included:

CONFIG_HAVE_PERF_EVENTS=y CONFIG_PERF_USE_VMALLOC=y CONFIG_PERF_EVENTS=y CONFIG_PERF_COUNTERS=y 

I also cross compiled the perf tool. The problem is that when I run the following command:

 perf stat ls 

The output does not seem to be correct:

 Performance counter stats for 'ls': 10887392 cycles # 0.000 Ghz 0 instructions # 0.00 insns per cycle 0.012448321 seconds time elapsed 

I set the processor policies to "userpace" and did:

 cpufreq-set -f 1600000 

to ensure that all cores always run at maximum frequency.

I would appreciate any help.

Here are links to similar cases without a solution: http://lists.linaro.org/pipermail/linaro-kernel/2012-December/002611.html http://forums.arm.com/index.php?/topic/15020- pmu-in-cortex-a8-omap-3530-what-am-i-doing-wrong /

Relevant stackoverflow topic: How to measure program runtime on an ARM Cortex-A8 processor?

Answer 1

Can you see other HW events like "CPU Cycles" or "Cache Flaws"?

 perf stat -e cache-misses,cycles ls 

You might also want to set CONFIG_HW_PERF_EVENTS.