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

From: Wangnan (F)
Date: Mon Nov 14 2016 - 23:33:16 EST




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.