Re: [PATCH] 2.6.0-test4 -- add context switch counters

[William Lee Irwin III <wli@holomorphy.com>]

On Wed, Aug 27, 2003 at 08:52:46AM -0700, Larry McVoy wrote:
> I normally hate ifdefs but this might be a good place to use a bunch of 
> macros and make them conditional on config_stats or something.  Updating
> counters is going to add to the size of the data cache footprint and it
> would be nice, for those people working on embedded low speed processors,
> if they could config this out.  I personally would leave it in, I like
> this stats.  I just know that the path to slowness is paved one cache
> miss at a time.

I've profiled this and know the memory stats don't do any harm; the
rest I'd have to see profiled. AFAICT all the damage is done after
ticking mm->rss in the various pagetable copying/blitting operations,
and once we've taken that hit (in mainline!) the other counters are
noise-level. The integral counters are another story; I've not seen
those in action.


-- wli