Messages in this thread | | | From | Rusty Russell <> | Subject | Re: [PATCH][RFC] tracing: Enable tracepoints via module parameters | Date | Fri, 11 Mar 2011 10:03:09 +1030 |
| |
On Tue, 08 Mar 2011 17:18:04 -0500, Steven Rostedt <rostedt@goodmis.org> wrote: > A few months ago it was suggested to have a way to enable tracepoints in > a module when it is loaded. I tried various methods, but this one seems > to be the least intrusive. In fact, it requires no modification to the > module code.
This seems quite nice!
Importantly, do you like it better than the previous version? I like it because it doesn't touch my code, but that's not a fair test.
A few minor things: 1) Can we document this somewhere more persistent too? ftrace.txt? 2) Your documentation should probably just use "trace_foo_bar" and omit the "=1". Because we can :) 3) Can we share more with param_set_bool? Nice to have it in one place when someone decides the kernel really needs to accept "=true" or whatever. 4) =n should really unset the flag, so args fight correctly.
eg (wildly untested):
int ftrace_mod_param_set(const char *val, const struct kernel_param *kp) { struct ftrace_event_call *call = kp->arg; struct kernel_param bool_kp; bool set; int err;
/* We work exactly like param_set_bool. */ bool_kp.arg = &set; bool_kp.flags = KPARAM_ISBOOL; err = param_set_bool(val, &bool_kp); if (err) return err;
/* Set flag to tell ftrace to enable this event on init */ if (set) call->flags = TRACE_EVENT_FL_MOD_ENABLE; else call->flags &= ~TRACE_EVENT_FL_MOD_ENABLE;
return 0; }
Cheers, Rusty.
| |