fquestions

[Gary Kline]

On Wed, Dec 14, 2005 at 08:37:49PM -0500, Chuck Swiger wrote:
> Gary Kline wrote:
> > On Wed, Dec 14, 2005 at 01:42:21PM -0800, Kent Stewart wrote:
> [ ... ]
> > 	Does it make any sense to use O3 when compiling stuff,
> > 	when stuff includes world/kernel/drivers?  Does upping the
> > 	optimization make any significant difference in system 
> > 	performance, in other words?  Kent?  Anybody?
> 
> No.  You are likely to vastly increase the amount of time it takes to compile
> the system without gaining any performance that's noticable.  The system
> generally shouldn't be spending a lot of CPU in the kernel, anyway, compared
> with the amount of time running user-mode code.  (Firewalls and routers are a
> significant exception, however.)

	Good to know, thanks.  I have done a lot of tuning on my 
	DNS server.  When I upgrade, you've given me more to think about.

> 
> If you want your system to perform better, benchmark the work it's actually
> doing, and then tune from there.  Spending lots of time to optimize a part of
> the system that is already pretty efficient isn't going to do much, whereas
> solving the bottleneck will make a useful difference.
> 

	For some reason, using Gnome sometimes brings my test server to
	a crawl.  It's running Ubuntu and they say straight out that "Linux 
	is just a kernel."  Other than the kernel my test system has the
	same software as I've got here.   Here, I run ctwm and
	everything's snappy.  Are there any benchmark suite you'd
	recommend to see what's sucking up the most cycles?  On every
	platform, not just my test box (old e-machines:).    top is
	not very helpful.

	gary


-- 
   Gary Kline     kline at thought.org   www.thought.org     Public service Unix