> It might help if the user space APIs for accessing static tracepoints were
> able to fail with something equivalent to "tracepoint no longer available",
> and this was clearly documented
It's not an API in the sense of a programming interface, but the way
systemtap exposes tracepoints (and indeed any other event source such
as kprobes, utrace events, timers, ....), is that an attempt to attach
to a facility that does not exist/match results in just such an error
Systemtap also has some facilities to adapt to changes in kernels and
elsewhere, using both a preprocessor construct (similar to a #if
KERNEL_VERSION), and a syntax to specify a list of alternative sources
of the same events (the "?" and "!" operators in a probe point sequence).
So systemtap's use of tracepoints in no way imposes a requirement that
they be unmodified and permanent.