Perf性能統計

perf record -e cpu-clock -p [pid] -g

[ perf record: Woken up 95 times to write data ]
[ perf record: Captured and wrote 23.788 MB perf.data (~1039333 samples) ]

perf report -g

Samples: 188K of event 'cpu-clock', Event count (approx.): 47241750000                                                                                       
+   5.17%  xxxd  [kernel.kallsyms]          [k] SYSC_semtimedop                                                                                            +
+   4.58%  xxxd  [kernel.kallsyms]          [k] system_call_after_swapgs                                                                                   :
+   3.40%  xxxd  libc-2.17.so               [.] __GI___semop                                                                                               :
+   3.40%  xxxd  [kernel.kallsyms]          [k] copy_user_enhanced_fast_string                                                                             :
+   3.37%  xxxd  libxxx_x86.so.1  [.] shmem_hashtbl_find
+ ……