Messages in this thread | | | Subject | Re: perf test BPF failing on f24: fix | From | "Wangnan (F)" <> | Date | Thu, 4 Aug 2016 09:50:25 +0800 |
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On 2016/8/4 7:08, Masami Hiramatsu wrote: > On Wed, 3 Aug 2016 23:45:57 +0900 > Masami Hiramatsu <mhiramat@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 >
Have you checked 'readelf -wi'? I guess you wouldn't find sys_epoll_wait.
Thank you.
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