Optimizationn questions?

Jerry McAllister jerrymc at msu.edu
Fri Mar 16 15:00:43 UTC 2007

On Fri, Mar 16, 2007 at 02:19:25AM +0100, Danny Pansters wrote:

> On Friday 16 March 2007 01:04:51 Jeffrey Goldberg wrote:
> > On Mar 15, 2007, at 5:21 PM, Jorn Argelo wrote:
> > > youshi10 at u.washington.edu wrote:
> > >> On Thu, 15 Mar 2007, Danny Pansters wrote:
> > >>      I know that this has been discussed a few times before, but
> > >> IMO running a slightly stripped down kernel (i.e. custom, not
> > >> GENERIC) actually proves to be helpful in increasing boot times
> > >> (if options were added statically) and compile times if [(# of
> > >> options added) < (# of options in GENERIC)].
> > >
> > > I can confirm this too. I noticed on both desktop and servers the
> > > boot time can be decreased by stripping the kernel configuration of
> > > stuff you don't need. I don't have any hard facts to prove this but
> > > this is what my personal experience is.
> >
> > me, too.
> >
> Of course it will speed up booting but then again how much time does one spend 
> booting, compared to using the puter: not much (at least I hope so for them!)
> If I do build my own kernel, for example to switch schedulers, I tend to toss 
> out a heap of devices that I don't have anyway. But other than a bit more 
> memory usage (which compared to the software that's run will typically be 
> minor anyhow unless you're talking embedded system or maybe not-so-embedded 
> but still of low spec special purpose boxes, like a satellite receiver box) 
> you're not going to have a slower system because your kernel happens to have 
> some built-in drivers that it doesn't use. The exception is a debug kernel of 
> course that will impact performance because it increases runtime tasks/load.
> On a server I'd strip down the kernel, but for other reasons (avoiding any 
> unneeded complexity). On a desktop I don't care as long as thingie works. 
> YMMV of course.

I think what he was saying is that if you already need to build a
kernel for some other reason, then go ahead and strip out the 
unused stuff.   But, if you don't have any other reason to do it,
it is not worth the bother to build another kernel just to strip
it of unused stuff - that it won't make THAT much difference.

I'd agree with that.   


> Dan
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