Re: [PATCH 0/7] [RFC] kernel: add a netlink interface to get information about processes

On Tue, Feb 17, 2015 at 09:09:47AM -0700, David Ahern wrote:

On 2/17/15 1:20 AM, Andrey Vagin wrote:

quoted

And here are statistics about syscalls which were called by each
command.
$ perf stat -e syscalls:sys_exit* -- ps ax -o pid,ppid  2>&1 | grep syscalls | sort -n -r | head -n 5
            20,713      syscalls:sys_exit_open
            20,710      syscalls:sys_exit_close
            20,708      syscalls:sys_exit_read
            10,348      syscalls:sys_exit_newstat
                31      syscalls:sys_exit_write

$ perf stat -e syscalls:sys_exit* -- ./task_diag_all  2>&1 | grep syscalls | sort -n -r | head -n 5
               114      syscalls:sys_exit_recvfrom
                49      syscalls:sys_exit_write
                 8      syscalls:sys_exit_mmap
                 4      syscalls:sys_exit_mprotect
                 3      syscalls:sys_exit_newfstat

'perf trace -s' gives the summary with stats.
e.g., perf trace -s --  ps ax -o pid,ppid

Thank you for this command, I haven't used it before.

 ps (21301), 145271 events, 100.0%, 0.000 msec

   syscall            calls      min       avg       max      stddev
                               (msec)    (msec)    (msec)        (%)
   --------------- -------- --------- --------- ---------     ------
   read               20717     0.000     0.020     1.631      0.64%
   write                  1     0.019     0.019     0.019      0.00%
   open               20722     0.025     0.035     3.624      0.93%
   close              20719     0.006     0.009     1.059      0.95%
   stat               10352     0.015     0.025     1.748      0.95%
   fstat                 12     0.010     0.012     0.020      6.17%
   lseek                  2     0.011     0.012     0.012      3.08%
   mmap                  30     0.012     0.034     0.094      9.35%
   mprotect              17     0.034     0.045     0.067      4.86%
   munmap                 3     0.028     0.058     0.108     44.12%
   brk                    4     0.011     0.015     0.019     11.24%
   rt_sigaction          25     0.011     0.011     0.014      1.27%
   rt_sigprocmask         1     0.012     0.012     0.012      0.00%
   ioctl                  4     0.010     0.012     0.014      6.94%
   access                 1     0.034     0.034     0.034      0.00%
   execve                 6     0.000     0.496     2.794     92.58%
   uname                  1     0.015     0.015     0.015      0.00%
   getdents              12     0.019     0.691     1.158     13.04%
   getrlimit              1     0.012     0.012     0.012      0.00%
   geteuid                1     0.012     0.012     0.012      0.00%
   arch_prctl             1     0.013     0.013     0.013      0.00%
   futex                  1     0.020     0.020     0.020      0.00%
   set_tid_address        1     0.012     0.012     0.012      0.00%
   openat                 1     0.030     0.030     0.030      0.00%
   set_robust_list        1     0.011     0.011     0.011      0.00%


 task_diag_all (21304), 569 events, 98.6%, 0.000 msec

   syscall            calls      min       avg       max      stddev
                               (msec)    (msec)    (msec)        (%)
   --------------- -------- --------- --------- ---------     ------
   read                   2     0.000     0.045     0.090    100.00%
   write                 77     0.010     0.013     0.083      7.93%
   open                   2     0.031     0.038     0.045     19.64%
   close                  3     0.010     0.014     0.017     13.43%
   fstat                  3     0.011     0.011     0.012      3.79%
   mmap                   8     0.013     0.027     0.049     16.72%
   mprotect               4     0.034     0.043     0.052      8.86%
   munmap                 1     0.031     0.031     0.031      0.00%
   brk                    1     0.014     0.014     0.014      0.00%
   ioctl                  1     0.010     0.010     0.010      0.00%
   access                 1     0.030     0.030     0.030      0.00%
   getpid                 1     0.011     0.011     0.011      0.00%
   socket                 1     0.045     0.045     0.045      0.00%
   sendto                 2     0.091     0.104     0.117     12.63%
   recvfrom             175     0.026     0.093     0.141      1.10%
   bind                   1     0.014     0.014     0.014      0.00%
   execve                 1     0.000     0.000     0.000      0.00%
   arch_prctl             1     0.011     0.011     0.011      0.00%

 ps (23850), 3117 events, 99.3%, 0.000 msec

   syscall            calls      min       avg       max      stddev
                               (msec)    (msec)    (msec)        (%)
   --------------- -------- --------- --------- ---------     ------
   read                 353     0.000     0.010     0.035      3.14%
   write                166     0.006     0.012     0.045      3.03%
   open                 365     0.002     0.005     0.178     11.29%
   close                354     0.001     0.002     0.024      3.57%
   stat                 170     0.002     0.007     0.662     52.99%
   fstat                 19     0.002     0.003     0.003      2.31%
   lseek                  2     0.003     0.003     0.003      6.49%
   mmap                  50     0.004     0.006     0.013      3.40%
...