profile是用于追踪程序执行调用流程的工具,类似于perf中的-g指令
相比perf -g而言,profile功能化更加细分,可以根据需要选择追踪层面,例如-U(用户要调用流程) -K (内核态调用流程)
下面具体介绍该工具的使用
采用profile --help,我们可以看到如下介绍:
usage: profile [-h] [-p PID] [-U | -K] [-F FREQUENCY | -c COUNT] [-d] [-a] [-f] [--stack-storage-size STACK_STORAGE_SIZE] [-C CPU] [duration] Profile CPU stack traces at a timed interval positional arguments: duration duration of trace, in seconds # profile的持续时间 optional arguments: -h, --help show this help message and exit -p PID, --pid PID profile this PID only # 只追踪该pid的调用流程 -U, --user-stacks-only # 查看用户态函数调用流程 show stacks from user space only (no kernel space stacks) -K, --kernel-stacks-only # 只查看内核态调用流程 show stacks from kernel space only (no user space stacks) -F FREQUENCY, --frequency FREQUENCY # profile追踪采样频率 例如: -F 99 表示按照99hz的频率进行采样,默认是采用的49hz sample frequency, Hertz -c COUNT, --count COUNT # 选择采样次数 -c 5表示在周期内采样5次,-c和-F两者不能同时使用 sample period, number of events -d, --delimited insert delimiter between kernel/user stacks # 在内核和用户态之间插入分界符 “---” -a, --annotations add _[k] annotations to kernel frames # 在显示的内核函数后面标记 '[k]'标识 -f, --folded output folded format, one line per stack (for flame #采用横向线上模式 xxx;xxx_1;xxxxx_2 graphs) --stack-storage-size STACK_STORAGE_SIZE # 设置调用栈的使用空间和默认支持空间大小 the number of unique stack traces that can be stored and displayed (default 16384) -C CPU, --cpu CPU cpu number to run profile on # 允许几个cpu运行profile程序 examples: ./profile # profile stack traces at 49 Hertz until Ctrl-C ./profile -F 99 # profile stack traces at 99 Hertz ./profile -c 1000000 # profile stack traces every 1 in a million events ./profile 5 # profile at 49 Hertz for 5 seconds only ./profile -f 5 # output in folded format for flame graphs ./profile -p 185 # only profile threads for PID 185 ./profile -U # only show user space stacks (no kernel) ./profile -K # only show kernel space stacks (no user)