perf

I'm doing event-based sampling with the perf userland tool: the objective being trying to find out where certain performance-impacting events like branch misses and cache misses are occurring on a larger system I'm working on. Now, something like perf record -a -e branch-misses:pp -- sleep 5 works perfectly: the PEBS counting mode trigerred by the 'pp' modifier is really accurate when collecting the IP in the samples. Unfortunately, when I try to do the same for cache-misses, i.e. perf record -a -e cache-misses:pp -- sleep 5 # [1] I get Error: sys_perf_event_open() syscall returned with 22

When running perf it finds the kernel symbols and symbols of my program but it does not find external module symbols. I have written a kernel module which I load using insmod how can I tell perf to find its symbols as well? I am running a 2.6.37.6 kernel (can't upgrade), my perf does not yet support the dwarf option but I think its a symbol issue. I have compiled everything with -g -fno-omit-frame-pointer I had to make it a kernel module, then perf could find its symbols: IN_TREE_DIR=/lib/modules/`uname -r`/kernel/modulename mkdir -p $IN_TREE_DIR cp modulename.ko $IN_TREE_DIR depmod -a 来源：

I tried giving the below command from container and found the below issue, may be because of "-moby" kernel version. Can't we get a docker image without word "-moby" coming in linux kernel version. I tried installing linux perf tool on VM having ubuntu and it worked. #docker run -t -i ubuntu:14.04 /bin/bash root@214daea94f4f:/# perf WARNING: perf not found for kernel 4.9.41 You may need to install the following packages for this specific kernel: linux-tools-4.9.41-moby linux-cloud-tools-4.9.41-moby You may also want to install one of the following packages to keep up to date: linux-tools-moby

I am using perf 3.0.4 on ubuntu 11.10. Its record command works well and displays on terminal 256 samples collected. But when I make use of perf report , it gives me the following error: perf.data file has no samples I searched a lot for the solution but no success yet. This thread has some useful information: http://www.spinics.net/lists/linux-perf-users/msg01436.html It seems that if you are running in a VM that does not expose the PMU to the guest, the default collection ( -e cycles ) won't work. Try running with -e cpu-clock . According to that thread, the OP had the same problem also in a

https://pingcap.com/blog-cn/flame-graph/ 因为 TiKV 是自己内部使用了 jemalloc，并没有用系统的 malloc，所以我们不能直接用 perf 来探查系统的 malloc 函数。幸运的是，perf 能支持动态添加探针，我们将 TiKV 的 malloc 加入： perf probe -x /deploy/bin/tikv-server -a malloc 来源： https://www.cnblogs.com/yuanjiangw/p/11826771.html

For example, def test(): print "test" I used perf record -g -p $pid , but the result was just all about PyEval_EvalFrameEx . How can I get the real name "test" or if can not by using perf? As of 2018, perf simply doesn't have support for reading the Python stack frames (cf. a 2014 Python mailinglist discussion ). Python 3.6 has some support for Dtrace and Systemtap . An alternative to this is Pyflame, a stochastic profiler for Python that samples python call stacks via ptrace() . In contrast to Dtrace/Systemtap you don't need extra permissions and it also works with Python versions that are