[RFC]-Approaches to user space probes

[Frank Ch. Eigler]

Hi -

anil.s.keshavamurthy wrote:

> [...]  I am not an expert in Java or Java probes, but before we lock
> down this approach I am suggesting that if possible we get feedback
> from JVM gurus too.

OK, but to involve them at this stage, we have to first formulate the
issue in a form they can understand.  Beyond asking them to add a few
hooks into their various interpreters (similarly to dtrace), how do
you think they might be impacted?


> [...] having a counter to count the missed probe does not solve the
> problem here.

Which problem?  That this can occur (with some low probability?)?
That it may be difficult to detect after occurrence?  That it may
be hard for a user to work around (rerunning may not work)?

> [...] In other words we should not see rp->nmissed > 0, however it
> is okay to for rp->kp.nmissed > 0.

While we may *prefer* not to see any nmissed > 0, how bad do you think
the consequences are if we do miss a few?  What are the odds?


- FChE