Re: [PATCH 00/34] perf clang: Builtin clang and perfhook support

["Wangnan (F)" <wangnan0@huawei.com>]

On 2016/11/15 12:05, Wang Nan wrote:
>    $ sudo -s
>    # ulimit -l unlimited
>    # perf record -e ./count_syscalls.c echo "Haha"
>    Start count, perfpid=25209
>    Haha
>    [ perf record: Woken up 1 times to write data ]
>    syscall 8	count: 6
>    syscall 11	count: 1
>    syscall 4	count: 6
>    syscall 21	count: 1
>    syscall 5	count: 3
>    syscall 231	count: 1
>    syscall 45	count: 3
>    syscall 0	count: 24
>    syscall 257	count: 1
>    syscall 59	count: 4
>    syscall 23	count: 9
>    syscall 78	count: 2
>    syscall 41	count: 4
>    syscall 72	count: 8
>    syscall 10	count: 3
>    syscall 321	count: 1
>    syscall 298	count: 7
>    syscall 16	count: 21
>    syscall 9	count: 16
>    syscall 1	count: 114
>    syscall 12	count: 3
>    syscall 14	count: 35
>    syscall 158	count: 1
>    syscall 2	count: 15
>    syscall 7	count: 18
>    syscall 3	count: 11
>    [ perf record: Captured and wrote 0.011 MB perf.data ]

Note that this example counts system wide syscall histogram, not
only 'echo' proc. The in-kernel BPF script doesn't know pid of 'echo'
so can't filter base on it. I'm planning adding more perf hook points
to pass information like this.

Thank you.