I was hoping we could establish consensus on a few notions
and priorities.
- that we want to build a great tool for both
performance tuning and for kernel debugging
- special needs for kernel debugging include
- must be able to instrument anywhere
- must be able to read or write any kernel data
- requires minimum restrictions on kernel routines
that can be invoked from a tap
- other needs?
- special needs for performance tool users include:
- safe: systemtap is broken if it is possible to
crash or damage the system
- fast: many useful tools have overhead < 5%
- easy to use: can do many useful things without the
need to read kernel source. I can run scripts from
3rd parties without fear.
- need timer events, stack walk into user space, tap
sets for key OS abstractions: system calls, I/O,
synch, scheduler, network, ...
- other needs?
Questions: Do we agree we want to try to meet the needs
of both kinds of users? What kind of options or auxilliary
components can we use to give these substantially different
perspectives for the two groups of users? When there is a
conflict, do we prioritize needs of one kind of user over
the other?
Brad