Does Android systrace require root access?

Question

I am trying to run systrace on a non-rooted device. It always gives the following error if any of the trace events is selected:

Unable to find trace start marker 'TRACE:': error opening /sys/kernel/debug/tracing/events/cpufreq_interactive/enable: No such file or directory

If no trace event is selected, it works, but the trace is not very usweful.

Does systrace requires root access?

Note that I am running systrace directly from Eclipse (DDMS) on Windows-7.

Answer 1

According to systrace.py --help, the following traces require root access:

• -d, --disk: trace disk I/O (requires root)
• -u, --bus-utilization: trace bus utilization (requires root)
• -w, --workqueue: trace the kernel workqueues (requires root)

The other options don't specify that a root access is required.

This said, I can use some of the traces (such as --cpu-freq), but I am unfortunately interested in --cpu-load which gives me the very same error as you mentioned.