環境：ubuntu16.04
1.在terminal輸入如下命令，安裝與當前內核版本一致的工具
sudo apt-get install linux-tools-common
sudo apt-get install linux-tools-"$(uname -r)"
sudo apt-get install linux-cloud-tools-"$(uname -r)"
sudo apt-get install linux-tools-generic
sudo apt-get install linux-cloud-tools-generic
安裝完成后，terminal輸入perf，可以顯示perf的用法介紹。
2.一般環境中，安裝完成后，使用perf top/perf record是不能正常工作的：
WARNING: Kernel address maps (/proc/{kallsyms,modules}) are restricted,
check /proc/sys/kernel/kptr_restrict.
Samples in kernel functions may not be resolved if a suitable vmlinux
file is not found in the buildid cache or in the vmlinux path.
Samples in kernel modules won't be resolved at all.
If some relocation was applied (e.g. kexec) symbols may be misresolved
even with a suitable vmlinux or kallsyms file.
perf_event_open(..., PERF_FLAG_FD_CLOEXEC) failed with unexpected error 13 (Permission denied)
perf_event_open(..., 0) failed unexpectedly with error 13 (Permission denied)
Error:
You may not have permission to collect stats.
Consider tweaking /proc/sys/kernel/perf_event_paranoid,
which controls use of the performance events system by
unprivileged users (without CAP_SYS_ADMIN).
The current value is 3:
-1: Allow use of (almost) all events by all users
Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK
>= 0: Disallow ftrace function tracepoint by users without CAP_SYS_ADMIN
Disallow raw tracepoint access by users without CAP_SYS_ADMIN
>= 1: Disallow CPU event access by users without CAP_SYS_ADMIN
>= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN
To make this setting permanent, edit /etc/sysctl.conf too, e.g.:
kernel.perf_event_paranoid = -1
兩種解決方法：
（1）使用sudo權限，如sudo perf top。
（2）設置kenel.perf_event_paranoid：
（2.1）臨時設置，需要sudo su切換到root用戶后再進行如下操作，操作完成后返回原用戶，此時輸入perf top可以正常工作。該方法系統重啟后失效。
如果是ubuntu16.04系統：
echo 0 > /proc/sys/kernel/kptr_restrict
echo -1 > /proc/sys/kernel/perf_event_paranoid
如果是ubuntu18.04系統（未實測）：
echo -1 > /proc/sys/kernel/perf_event_paranoid
（2.2）修改配置文件，重啟后仍有效。
編輯/etc/sysctl.conf，在文件末尾加上：
kernel.kptr_restrict=0 （如果是ubuntu16.04則加入該配置）
kernel.perf_event_paranoid= -1
最后，使用sysctl -p /etc/sysctl.conf命令reload配置文件。
參考：