Re: [PATCH]: O(1) 2.4.17-J7 Tuneable Parameters

[Rob Landley]

On Wednesday 30 January 2002 08:21 am, Martin Knoblauch wrote:
> > [PATCH]: O(1) 2.4.17-J7 Tuneable Parameters
> >
> >
> > Hi Ingo,
> >
> >         This patch synchronizes with J7 and I think makes the changes
> > you wished. A couple of important points:
> >
> >                 - This patch can be applied to EITHER 2.4.17 OR 2.4.18
> > pre 7 as long as Ingo's J7 patch is applied first.
> >
> >                 - While I agree with you on not wanting these in the
> > mainline kernel, I ran Hackbench on one of our new Foster systems with
> > and without the tuneable parameters, and while the numbers do degrade
> > slightly, its rather suprisingly small. So dont be afraid to use this as
> > a system tuning aid.
>
>  How big is the actual degradation in your test? IIR, Ingo is afraid
> that the tunables could easily screw things up, which of course is true.
> What about adding a kernel-build option that leaves the sysctl interface
> read-only by default and enables writing only if it is requested at
> build time?

Nah, as long as the permissions say only root can write to it, you're pretty 
much covered.  (It's certainly no worse than root going cat /dev/zero > 
/dev/hda...)

Rob