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Do I need to have to run perf userspace tool as system administrator (root), or can I run it (or at least some subcommands) as an ordinary user?

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Unix programs that can't do what they need to do for lack of permissions will usually thrown an error if they can't do their job. Run it and see! –  Caleb Jun 2 '11 at 10:55
    
I am asking this question to decide whether it is worth trying to install (as ordinary user, in $HOME) userspace part of perf tool (which is/can be non-trivial). –  Jakub Narębski Jun 2 '11 at 12:19
    
FYI in Ubuntu perf is in linux-tools package, so installing perf there is simple. –  Jakub Narębski Jun 12 '13 at 16:59

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up vote 6 down vote accepted

What you can do with perf without being root depends on the kernel.perf_event_paranoid sysctl setting.

  • kernel.perf_event_paranoid = 2: you can't take any measurements. The perf utility might still be useful to analyse existing records with perf ls, perf report, perf timechart or perf trace.
  • kernel.perf_event_paranoid = 1: you can trace a command with perf stat or perf record, and get kernel profiling data.
  • kernel.perf_event_paranoid = 0: you can trace a command with perf stat or perf record, and get CPU event data.
  • kernel.perf_event_paranoid = -1: you get raw access to kernel tracepoints (specifically, you can mmap the file created by perf_event_open, I don't know what the implications are).
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Nice. cat /proc/sys/kernel/perf_event_paranoid returns 1, so it seems that I would be able to take at least some measurements (BTW. whats the difference betwen "kernel profiling data" and "CPU event data"? Reference is enough) –  Jakub Narębski Jun 2 '11 at 17:48
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@Jakub: From what I understand, kernel events let you see calls to various kernel functions. CPU events are counters in the CPU that tell you how many times a particular location in memory was hit. I've never used them, so I can't tell you more about them; LWN has quite a few article on the topic, and it's still evolving. –  Gilles Jun 2 '11 at 18:03

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