tree b9f43f403f2482e4df7505019e47c749fae9ec8b
parent 67cc2ff4e4cc4bbdedaba8576879a531a9dc1056
author Yonghong Song <yhs@fb.com> 1524830168 -0700
committer Yonghong Song <yhs@fb.com> 1524991054 -0700

introduce {attach|detach}_raw_tracepoint API

The motivation comes from pull request #1689.
It attached a kprobe bpf program to kernel function
ttwu_do_wakeup for more accurate tracing.
Unfortunately, it broke runqlat.py in my
4.17 environment since ttwu_do_wakeup function
is inlined in my kernel with gcc 7.3.1.

4.17 introduced raw_tracepoint and this patch
added the relevant API to bcc. With this,
we can use tracepoints
sched:{sched_wakeup, sched_wakeup_new, sched_switch}
to measure runq latency more reliably.

Signed-off-by: Yonghong Song <yhs@fb.com>