Unknown error using opensnoop about perf-tools

[cebtenzzre]

CONFIG_FTRACE_SYSCALLS may be necessary. That's disabled on my system and I get this error. I'll rebuild my kernel with it enabled and see what happens.

Edit: Yes, enabling CONFIG_FTRACE_SYSCALLS (and CONFIG_FUNCTION_PROFILER, though it probably wasn't necessary) solved the problem.

[mpictor]

$ sudo ./opensnoop
Password:
Tracing open()s. Ctrl-C to end.
./opensnoop: line 179: events/syscalls/sys_exit_open/enable: No such file or directory
ERROR: enabling open() exit tracepoint. Exiting.

opensnoop:179 is

if ! echo 1 > events/syscalls/sys_exit_open/enable; then

Not sure how this ever worked...?!

[scotte]

Is FTRACE enabled in your kernel?

[mpictor]

It appears CONFIG_FTRACE_SYSCALLS wasn't enabled in my kernel (though the waters are a bit muddy - the repo containing the config was reorganized a few times).

I'll try to find time to try again.

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Not sure how this ever worked...?!

I think I was referring to the relative path. Seems I hadn't noticed the cd /sys/... command. 😳