perf trace跟踪系统调用

perf trace -p $pid --duration 50 
           

命令输出如下：

0.076 (1249.922 ms): epoll_wait(epfd: 4<anon_inode:[eventpoll]>, events: 0x7ffe92ab3af0, maxevents: 36, timeout: 4294967295) = 1
  1250.074 (1249.927 ms): epoll_wait(epfd: 4<anon_inode:[eventpoll]>, events: 0x7ffe92ab3af0, maxevents: 36, timeout: 4294967295) = 1
  2500.076 (1249.924 ms): epoll_wait(epfd: 4<anon_inode:[eventpoll]>, events: 0x7ffe92ab3af0, maxevents: 36, timeout: 4294967295) = 1
           

perf trace -p $pid --duration 50 --call-graph dwarf -o savefile.txt
           

命令输出如下：

0.409 (1249.593 ms): epoll_wait(epfd: 4<anon_inode:[eventpoll]>, events: 0x7ffe92ab3af0, maxevents: 36, timeout: 4294967295) = 1
                                       [0xffff80d79646ceb3] (/usr/lib64/libc-2.17.so)
                                       [0xffffaa31d86cf058] (/usr/lib/systemd/systemd)
                                       [0xffffaa31d86cfb6c] (/usr/lib/systemd/systemd)
                                       [0xffffaa31d862db82] (/usr/lib/systemd/systemd)
                                       [0xffffaa31d8621f27] (/usr/lib/systemd/systemd)
                                       __libc_start_main (/usr/lib64/libc-2.17.so)
                                       [0xffffaa31d8623f8b] (/usr/lib/systemd/systemd)