Re: tapset feedback

[Martin Hunt <hunt at redhat dot com>]

On Thu, 2006-01-05 at 01:05 -0800, Roland McGrath wrote:
> > One thing I would recommend is a conceptual split between "tapsets",
> > which export probe points and a system library, which would export
> > general-purpose safe functions.
> 
> Why is this advantageous?  The problems you've cited argue for some kind of
> name spaces or module system for systemtap functions and probes.  But I
> don't off hand see how they lead you to conclude that distinguishing these
> two kinds of libraries (function libraries, and probe libraries, which some
> people like to call tapsets).  

All I'm proposing is that we have a well-defined and documented set of
library functions.  And regardless of how it is implemented, I don't
think we should call it a tapset because it doesn't act like a tapset.

> > A. What if one of the functions matched does not exist in the current
> > kernel?  Right now the compilation fails.
> 
> What does that mean?  A wildcard match will produce some set of actual
> probe points, and all of those will exist in the kernel that matches the
> debuginfo examined.  

I'm thinking about tapsets here. For example, "kernel.syscall.*" may
contain functions that the current kernel doesn't implement.

Martin