一、在ubuntu中使用apt包下载Perf

输入perf命令，提示：

Command 'perf' not found, but can be installed with:apt install linux-tools-common
Please ask your administrator.

按照提示安装linux-tools-common:

sudo apt-get install linux-tools-common

查看perf -v，提示：

WARNING: perf not found for kernel 5.4.0-150You may need to install the following packages for this specific kernel:linux-tools-5.4.0-150-genericlinux-cloud-tools-5.4.0-150-genericYou may also want to install one of the following packages to keep up to date:linux-tools-genericlinux-cloud-tools-generic

由于linux有不同的发行版本，内核工具也不同，提示的意思是可以下载特定的内核版本下的tools，根据命令行的提示，使用uname -r 查看内核版本，并下载

sudo apt-get install linux-tools-5.4.0-150-generic

再次执行perf -v可以得到当前版本

perf version 5.4.233

参考博文：Perf的安装与简单使用

二、使用源码安装Perf，并移植到arm-linux环境下

perf是一种系统级性能分析工具，它涉及内核调用，所以安装需要知道内核版本。查看arm-linux平台的内核的版本，到官网上去下载特定的内核源码

在开发板终端输入

uname -r
5.4.31

去官网上下载内核源码，可以手动下载，也可以使用wget，以下操作在ubuntu平台

Linux内核源码下载网站：Index of /sites/ftp.kernel.org/pub/linux/kernel/ (sjtu.edu.cn) 或者 Index of /kernel/linux/kernel/
wget下载，例如：wget http://ftp.sjtu.edu.cn/sites/ftp.kernel.org/pub/linux/kernel/v5.x/linux-5.4.31.tar.gz

下载完毕之后，解压内核源代码

tar -zxvf linux-5.4.31.tar.gz

进入如下目录

cd linux-5.4.31/tools/perf/

修改Makefile.conf文件，添加LIBC_SUPPORT := 1

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源码级安装，如有些依赖包没有安装，得安装一下，Perf源码安装的依赖：ubuntu源码安装性能分析工具perf - 知乎 (zhihu.com)

make -j4 && make install

当前文件夹生成perf应用，

file perf

输出结果：
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将编译得到的应用发送到开发板上，运行成功

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如果遇到其他问题可以参考博文：
linux perf arm,perf arm交叉编译

perf使用的博文：
perf性能分析工具使用分享
打卡不停更#Linux perf工具使用
perf学习-linux自带性能分析工具

三、使用perf

编写示例程序

#include <stdio.h>
void print(void)
{int i = 0;while(1){i++;}
}
int main ()
{print();return 0;
}

编译目标位可执行文件

gcc -g test.c -o test

使用perf分析性能

perf stat test

出现报错

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 usersIgnore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK
>= 0: Disallow ftrace function tracepoint by users without CAP_SYS_ADMINDisallow 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_ADMINTo make this setting permanent, edit /etc/sysctl.conf too, e.g.:kernel.perf_event_paranoid = -1

根据提示到指定文件夹中查找该变量，发现没有，经过百度后替换perf_event_paranoid文件夹内容为-1，注意修改内核文件要加sudo
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参考博文：perf have no permission to collect stats

重新执行

perf stat test

输出结果如下

Performance counter stats for 'test':0.74 msec task-clock                #    0.484 CPUs utilized          0      context-switches          #    0.000 K/sec                  0      cpu-migrations            #    0.000 K/sec                  58      page-faults               #    0.079 M/sec                  <not supported>      cycles                                                      <not supported>      instructions                                                <not supported>      branches                                                    <not supported>      branch-misses                                               0.001520723 seconds time elapsed0.001628000 seconds user0.000000000 seconds sys

四、Perf的功能介绍

可以使用许多 perf 命令来获取有关 CPU 使用情况、内存使用情况、I/O 使用情况等信息

>$ perf --helpusage: perf [--version] [--help] [OPTIONS] COMMAND [ARGS]The most commonly used perf commands are:annotate        Read perf.data (created by perf record) and display annotated codearchive         Create archive with object files with build-ids found in perf.data filebench           General framework for benchmark suitesbuildid-cache   Manage build-id cache.buildid-list    List the buildids in a perf.data filec2c             Shared Data C2C/HITM Analyzer.config          Get and set variables in a configuration file.data            Data file related processingdiff            Read perf.data files and display the differential profileevlist          List the event names in a perf.data fileftrace          simple wrapper for kernel's ftrace functionalityinject          Filter to augment the events stream with additional informationkallsyms        Searches running kernel for symbolskmem            Tool to trace/measure kernel memory propertieskvm             Tool to trace/measure kvm guest oslist            List all symbolic event typeslock            Analyze lock eventsmem             Profile memory accessesrecord          Run a command and record its profile into perf.data #可以记录指定进程的指定事件report          Read perf.data (created by perf record) and display the profile #可以生成一份报告，显示前面记录的性能参数sched           Tool to trace/measure scheduler properties (latencies)script          Read perf.data (created by perf record) and display trace outputstat            Run a command and gather performance counter statistics  #可以查看指定命令的CPU和内存使用情况test            Runs sanity tests.timechart       Tool to visualize total system behavior during a workloadtop             System profiling tool.version         display the version of perf binaryprobe           Define new dynamic tracepointstrace           strace inspired toolSee 'perf help COMMAND' for more information on a specific command.