Unix and Linux Stack Exchange
Unix and Linux Stack Exchange

Questions tagged [perf-event]

perf_event is the Linux kernel library and tool to simplify access to performance monitoring utilities infrastructure.

31 questions
29
votes
1 answer

Do I need root (admin) permissions to run userspace 'perf' tool? (perf events are enabled in Linux kernel)

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?
Jakub Narębski
  • 1,228
  • 2
  • 17
  • 30
19
votes
1 answer

What are Kernel PMU event-s in perf_events list?

Searching for what one can monitor with perf_events on Linux, I cannot find what Kernel PMU event are? Namely, with perf version 3.13.11-ckt39 the perf list shows events like: branch-instructions OR cpu/branch-instructions/ [Kernel PMU…
xealits
  • 2,093
  • 3
  • 19
  • 27
10
votes
2 answers

Missing stack symbols with perf_event's perf report, despite -fno-omit-frame-pointer compilation

I'm struggling getting perf_events to give me stack traces with symbols, despite reading many tutorials on the subject and doing (I think) all the necessary things. It's possible that my local install of perf (details on that below) is somehow…
Kulluk007
  • 293
  • 2
  • 3
  • 8
7
votes
2 answers

Measure disk IO latencies of a running process

I'm trying to measure the disk IO latencies of a running process to make a histogram. I could do this with DTrace in operating systems that provide it (e.g. as in this Joyent paper), but my application is running in Linux. My first thought was to…
ajduff574
  • 223
  • 3
  • 7
6
votes
1 answer

How to check that perf events are enabled in Linux kernel, and how to install perf userland as non-root?

From what I have checked it looks like kernel side of 'perf' subsystem is enabled on computer I work on. Checking kernel configuration shows the following $ zgrep "_PERF[_= ]" /proc/config.gz CONFIG_HAVE_PERF_EVENTS=y CONFIG_PERF_EVENTS=y #…
Jakub Narębski
  • 1,228
  • 2
  • 17
  • 30
5
votes
1 answer

perf fails to work on really large process

I use perf quite often to profile my applications. Recently I got a few new machine with ~750G RAM each. I am trying to profile a process that uses about 400G of ram on one of them. This works fine on all the new machines but one. They were all…
Shlomi
  • 151
  • 1
  • 4
4
votes
2 answers

How to analyze profile data from `perf record --a` (system-wide collection)?

I am using perf from linux-2.6.36-gentoo-r4. The /proc/sys/kernel/perf_event_paranoid is set to 0, so there should be no problems from there. Because long-running application I am profiling sometimes crashes for some indetermined reason (no…
Jakub Narębski
  • 1,228
  • 2
  • 17
  • 30
4
votes
1 answer

Fail to install perf on slackware 13.1

I was trying to install perf on slackware 13.1 When I first ran make at /usr/src/linux/tools/perf I got some errors. And I found this patch http://www.valimar.it/repo/linux/perf_fix-2.6.33.patch And when I ran make again, it issued some different…
sleetdrop
  • 181
  • 5
3
votes
1 answer

Understanding Perf tool output

I recently installed Perf tool On my platform and wanted to use it for profiling my platform. I started profiling a standalone application. Below is the command I used: perf start ./helloworld Performance counter stats for './helloworld': …
Ram
  • 655
  • 4
  • 9
  • 19
3
votes
1 answer

Where Do I get Source package for Perf tool

I am looking for source package of perf tool ,which I wanted to compile for ARM Linux ,I have already set up the cross compile tool chain. I have compiled the the oprofile and got it source(Oprofile-0.9.8.tar.bz2) from sourceforge.net. Can anyone…
Ram
  • 655
  • 4
  • 9
  • 19
3
votes
0 answers

Problem in making Perf Kernel Counter work

I have written a kernel module which creates a performance counter via "perf_event_create_kernel_counter" API and then periodically reads its value. My application works on Kernel version-4.0.9 (and prior revisions) but it doesn't work on Kernel…
Skidro
  • 31
  • 2
2
votes
3 answers

Why can't I find hardware cache event in my perf list?

I have a problem in using linux perf on a newly bought laptop: there is no available hardware cache effect in my perf list!!! Well, this is really all important information that I wish to sample!! Here is my perf list: List of pre-defined events (to…
Zheyuan Li
  • 123
  • 1
  • 5
2
votes
2 answers

View current kernel parameters?

I saw in my syslog kernel.perf_event_max_sample_rate get changed. I was wondering if I could write a quick script to log this variable every few minutes. Currently it is: sysctl -a | grep kernel.perf_event_max_sample_rate In the man page sysctl…
pwnyrainbow
  • 55
  • 1
  • 1
  • 3
2
votes
0 answers

How does performance measurement tool 'perf' actually work?

perf is a tool which accesses the performance counter registers of an machine and gives out metrics to user to analyze the system performance. What I am curious about is, when I read the parts of code. I see perf reading something from a memory…
kakeh
  • 483
  • 7
  • 16
2
votes
1 answer

Understanding Unit Masks on Perf

I'm counting events with perf stat -e. I consulted my processor manufacturer's manual and found the event I'm interested in. However, not only does it have the event number, but it also has a list of unit masks and their descriptions. What are they…
iomartin
  • 163
  • 5
1
2 3