On Wed, 3 Aug 2016 23:45:57 +0900 Masami Hiramatsu <mhira...@kernel.org> wrote:
> > > [root@jouet ~]# perf probe sys_epoll_wait > > > Failed to find debug information for address ffffffffbd295b50 > > > Probe point 'sys_epoll_wait' not found. > > > Error: Failed to add events. > > So, at least I should investigate it. FYI, on ubuntu16.04, I can put probes on sys_epoll_wait as below mhiramat@devnote:~/ksrc/linux/tools/perf$ sudo ./perf probe -vnf sys_epoll_wait probe-definition(0): sys_epoll_wait symbol:sys_epoll_wait file:(null) line:0 offset:0 return:0 lazy:(null) 0 arguments Looking at the vmlinux_path (8 entries long) Using /usr/lib/debug/boot/vmlinux-4.4.0-31-generic for symbols Open Debuginfo file: /usr/lib/debug/boot/vmlinux-4.4.0-31-generic Try to find probe point from debuginfo. Symbol sys_epoll_wait address found : ffffffff81257410 Matched function: SyS_epoll_wait found inline addr: 0xffffffff81257410 Probe point found: SyS_epoll_wait+0 found inline addr: 0xffffffff8125756d Probe point found: SyS_epoll_pwait+141 found inline addr: 0xffffffff81257793 Probe point found: compat_SyS_epoll_pwait+147 Found 3 probe_trace_events. Opening /sys/kernel/debug/tracing//kprobe_events write=1 Writing event: p:probe/sys_epoll_wait _text+2454544 Writing event: p:probe/sys_epoll_wait_1 _text+2454893 Writing event: p:probe/sys_epoll_wait_2 _text+2455443 Added new events: probe:sys_epoll_wait (on sys_epoll_wait) probe:sys_epoll_wait_1 (on sys_epoll_wait) probe:sys_epoll_wait_2 (on sys_epoll_wait) You can now use it in all perf tools, such as: perf record -e probe:sys_epoll_wait_2 -aR sleep 1 -- Masami Hiramatsu <mhira...@kernel.org>