Re: [PATCH] 2.6.0 batch scheduling, HT aware

[davidsen@tmr.com (bill davidsen)]

In article <200312240909.19006.kernel@kolivas.org>,
Con Kolivas  <kernel@kolivas.org> wrote:
| On Wed, 24 Dec 2003 02:51, bill davidsen wrote:
| > There are two goals here. Not having a batch process on one siling makes
| > sense, and I'm going to try Con's patch after I try Nick's latest.
| > Actually, if they play nicely I would use both, batch would be very
| > useful for nightly report generation on servers.
| 
| No hope of them playing nicely, but at some later stage I might resync on top 
| of Nick's work if I like the direction it takes (which looks likely!)
| 
| > But WRT the whole HT scheduling, it would seem that ideally you want to
| > schedule the two (or N) processes which have the lowest aggregate cache
| > thrash, if you had a way to determine that. I suspect that a process
| > which had a small itterative inner loop with a code+data footprint of
| > 2-3k would coexist well with almost anything else. Minimizing the FPU
| > contention also would improve performance, no doubt. I don't know that
| > there are the tools at the moment to get this information, but it seems
| > as though until it's available any scheduling will be working in the
| > dark to some extent.
| 
| Impossible with current tools. Only userspace would have a chance of 
| predicting this and the simple rule we work off is that userspace can't be 
| trusted so this does not appear doable in the foreseeable future.

Glad you agree, but this makes improvement dificult.


-- 
bill davidsen <davidsen@tmr.com>
  CTO, TMR Associates, Inc
Doing interesting things with little computers since 1979.