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

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Wed, Apr 06, 2011 at 05:29:18PM +0100, Mindaugas Rasiukevicius wrote:
> Manuel Bouyer <bouyer%antioche.eu.org@localhost> wrote:
> > <...>
> > - I'm not sure you want to have dtrace running on a production server.
> > 
> > KMEMSTATS is more than pure debugging purpose, it also helps with
> > tuning, and figuring out temporary overload.
> 
> DTrace was *designed* as suitable for production systems.
> 
> It does not require to compile a debug kernel, which requires reboot and

not an issue: I compile it when I install or upgrade the system, so it's not
an extra reboot

> may be expensive to run.

I've not noticed any difference with KMEMSTATS for me.

> Unlike other debug facilities, dynamic probing
> does not change the function body - it is binary patching of entry/exit
> points and it is only temporarily while probing.

The point it: I don't want probes to be temporarily. When you notice a
problem it's too late to start the probe.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--