Re: extent-patch and overview of what is supposed to follow

[Thor Lancelot Simon <tls%panix.com@localhost>]

On Wed, Apr 06, 2011 at 06:34:15PM +0200, Manuel Bouyer wrote:
> 
> The point it: I don't want probes to be temporarily. When you notice a
> problem it's too late to start the probe.

How can you have both things you seem to want?  In your other message,
you seemed concerned that (you thought) DTrace was turned on for all
probes all the time, generating data.  But now it sounds like exactly what
you want is a debug facility that is turned on all the time, generating
data.

In practice, it is entirely feasible to have a small set of DTrace
probes always running.  Start them at boot time, let them run.  This
is the kind of case where the ability to summarize data (counts,
histograms, etc.) is so valuable, so you do not end up generating a
textual data stream that is output all the time as the system runs.