Bug#788653: RFS: ktap/0.4-1 [ITP] -- lightweight script-based dynamic tracing tool for Linux

[Azat Khuzhin <a3at.mail@gmail.com>]

On Sun, Sep 27, 2015 at 06:27:49PM +0000, Gianfranco Costamagna wrote:
> Hi,
> 
> > first a question: does the user need to do modprobe ktapvm manually?
> 
> 
> 
> well, can't the ktap tool do the job automagically?
> 
> and moreover, how do the user know that a ktap source has a ktapvm kernel module?
> 
> 
> 
> I mean, I would expect a kernel module called "ktap" and maybe a readme explaining me
> (maybe in man ktap) that it needs a magic autoprobe
> (or making it automatically load on system startup?)

I don't think that loading it at system startup is a good idea for now,
but maybe some day (basically all it does is handle requests to
/sys/kernel/debug/ktap/ktapvm but just in case I will not load it at
start).

As for man page, ktap will report next error:
$ ktap /usr/share/doc/ktap/samples/basic/backtrace.kp 
open /sys/kernel/debug/ktap/ktapvm failed: No such file or directory

But note in ktap(1) will be better, so added and uploaded to mentors:

"
...

NOTES
       To make ktap work, firstly you need to load "ktapvm" module:

              modprobe ktapvm

...
"

Thanks,
Azat.