lkml.org 
[lkml]   [2007]   [Apr]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [Announce] [patch] Modular Scheduler Core and Completely Fair Scheduler [CFS]
On Thu, 19 Apr 2007 05:18:07 +0200 Nick Piggin <npiggin@suse.de> wrote:

> And yes, by fairly, I mean fairly among all threads as a base resource
> class, because that's what Linux has always done

Yes, there are potential compatibility problems. Example: a machine with
100 busy httpd processes and suddenly a big gzip starts up from console or
cron.

Under current kernels, that gzip will take ages and the httpds will take a
1% slowdown, which may well be exactly the behaviour which is desired.

If we were to schedule by UID then the gzip suddenly gets 50% of the CPU
and those httpd's all take a 50% hit, which could be quite serious.

That's simple to fix via nicing, but people have to know to do that, and
there will be a transition period where some disruption is possible.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-04-19 07:19    [from the cache]
©2003-2011 Jasper Spaans