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Questions tagged [perf-event]

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

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152 views

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 ...
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1answer
533 views

perf error: failed to mmap with 25 (Inappropriate ioctl for device)

I am trying to use perf in a system with 3.8 linux kernel. When I used the following command, error happens: $ perf record -c 100000 -e '{cycles,instructions}:S' ./nonloop 1000 failed to mmap with 25 ...
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1answer
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What does `perf stat` option `--cpu` is actually showing?

I am trying to understand the --cpu option of perf-stat. In the man pages it says: Count only on the list of CPUs provided. Multiple CPUs can be provided as a comma-separated list with no space: ...
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0answers
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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 ...
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0answers
747 views

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 ...
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0answers
68 views

Bash check if firefox use internet

I want to check how much internet use Firefox with a shell script. Here I found good examples to see performances. #!/bin/sh free -m | awk 'NR==2{printf "Memory Usage: %s/%sMB (%.2f%%)\n", $3,$2,$3*...
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473 views

Perf Tool Linux - Not counting cycles-t and cycles-ct

am using the Linux Perf tool to monitor certain events for my benchmarking runs. In the event list argument -e, I added cycles-t and cycles-ct since I want to capture them. But both of them always ...