Questions tagged [perf]

perf is Linux profiling tool for both Linux kernel and underlying hardware (hardware counters).

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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
534 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
26 views

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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1answer
2k views

How do I generate the /sys/kernel/debug/tracing folder in kernel with yocto project?

I was tying to use perf on Renesas target and I configured the yocto "local.conf" as showed in this link. #avoid stripping binaries INHIBIT_PACKAGE_STRIP = "1" #add the debug information ...
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1answer
219 views

Linux tools for perf (install linux-tools-3.15.0)

I use Linaro version of Linux (Linaro 12.11) on my embedded target with ARM9 Core. For a certain profiling, I need to use the perf tool. perf require linux-tools-3.15.0 to be installed on my device. ...
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755 views

perf cycles not supported

I am trying to use perf for profiling in a Linux virtual machine. However, I am receiving the following output: [vagrant@localhost ~]$ perf stat -d ls / bin boot dev etc home lib lib64 lost+...
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0answers
737 views

How to interpret perf -e cache-misses:pp?

I find the behavior of perf top -e cache-misses:pp -p <my_pid> quite confusing. I own an Intel i5-3230M, running kernel 4.4.5 64 bit. If I just run that commmand, I get basically no samples ...
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160 views

Perf Tool monitoring by PID

I'm using linux perf tool to monitor the performance of some processes. The documentation tells that you can flag it to collect profiles on per-thread, per-process and per-cpu basis. I get that the ...
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246 views

Recording a process with perf using PID doesn't work

When I do performance profiling using perf, normally this works: perf record -g -F99 $BINARY_NAME Upon completion, the command says: [ perf record: Captured and wrote 0.006 MB output.data (37 ...
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0answers
669 views

Capturing screen of “perf top” or other interactive programs

I'm trying to write a script to capture output of perf top Similar to top, perf top detects the screen size and fill information to the screen. But sadly unlike top which has a batch mode, perf does ...
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23 views

Determine average and maximum execution time of a task by using ftrace/perf

I've gathered some traces containing scheduling events ('sched:*') by using ftrace and perf record. By analyzing the results many of my questions could already be answered. However, I was wondering ...
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Does `perf trace -p <PID>` trace all threads?

strace -f -p <PID> traces system calls in all threads of a multi-threaded process. (This also follows forks, there is an option -b execve that tries to address that). Does perf trace -p <...
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69 views

How could I add support for an event modifier in perf

I need to account power for the kernel space, but unfortunately the k modifier are not supported for the power/energy-cores/. I have an example of what I'm trying to do below. I'm reading the source ...
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0answers
116 views

Perf tool usage on A7 and A15 cores (Big.Little) on XU3/XU4 boards

Many people have posted on odroid forum and elsewhere on how to enable "perf" on XU3 and XU4 boards. After months of trials, one final solution was presented in http://forum.odroid.com/viewtopic.php?f=...
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61 views

perf-like assembly reading tool

perf has a very friendly terminal interface for performance analysis. It has a very helpful feature that the branch target is annotated with beautiful arrows, showing where this branch is going to (if ...
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134 views

perf_events over ssh (osx -> linux) freezing and unresponsive

I'm using linux perf_events and sometimes am having trouble with the perf report (which is a terminal application) view freezing up. I'm interacting with a remote linux server which is running perf ...
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0answers
100 views

Running perf on a custom kernel that does not come with /tools or gcc

I need to run some benchmarks on a hypervisor (Xtratum) Linux partition. The kernel version is 3.4.4-xm and comes as an SDK which I only need to path include in the hypervisor makefile. As noted in ...
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82 views

Is the perfmon2 tool obsolete due to the same functionality being included in the current Linux kernel?

I was having some issues with the PAPI tool and multiplex and this answer by the PAPI creator led me to check out perfmon2: http://lists.eecs.utk.edu/pipermail/ptools-perfapi/2008-April/000900.html ...
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565 views

RHEL6 Idle Thread Behavior

I am doing some cpu performance profiling with the perf tool on a RHEL6 box running weblogic12g. It looks like the idle threads are presented as native_safe_halt in the stack profile but ...
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0answers
474 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 ...
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203 views

unresolved symbols sudo perf record/report

I am trying to use perf to profile a program that I have written on a work server. I have sudo privilege but should limit what I do with it. $ rm perf.data $ perf record ./catch-hedging ...
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299 views

Run “perf top” on another user's process

We have a CentOS 7 system with two user accounts: Sally, to run production jobs. Tanya, for monitoring and interactive jobs. Sally runs a specific job that Tanya needs to monitor using perf top. ...