Re: get the mapping of <key, syscallname>

["Jose R. Santos" <jrs at us dot ibm dot com>]

Frank Ch. Eigler wrote:

> Hi -
>
> > > Why not use the "name" variable set by the syscalls tapset?
> >
> > LKET does not currently use the syscall tapset because it doesnt use the 
> > extra information that this tapset collects from each systemcall.  [...]
>
> But, due to the optimization pass in the translator, only that portion
> of the information actually *used* by your script is actually
> collected.  Please try it out (check out stap -p2 or -p3 output to
> confirm).
>  
I seem to remember that there was another reason why Li Guanglei did not 
use the systemcall tapset but I cant remember why.  If the performance 
is good, then adding the systemcall id number variable will solve this 
problem.  We'll, try it out.

> > [...]  Its not just the string printing that's costly, its also
> > searching the system call name with in CONTEXT->probe_point.  [...]
>
> Rolling your own code to manually scan through "probe_point" is not
> really necessary or appropriate.  There is a "probefunc()" function
> you can use for now.
>  
I agree.  Thats why I would like to see LKET as part of the SystemTap 
tapset in order to have more people reviewing some of the stupid design 
decisions we make. :)

> - FChE
>  

-JRS