lkml.org 
[lkml]   [2005]   [Apr]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [Patch] sched: remove unnecessary sched domains
Siddha, Suresh B wrote:
> Appended patch removes the unnecessary scheduler domains(containing
> only one sched group) setup during the sched-domain init.
>
> For example on x86_64, we always have NUMA configured in. On Intel EM64T
> systems, top most sched domain will be of NUMA and with only one sched_group in
> it.
>
> With fork/exec balances(recent Nick's fixes in -mm tree), we always endup
> taking wrong decisions because of this topmost domain (as it contains only
> one group and find_idlest_group always returns NULL). We will endup loading
> HT package completely first, letting active load balance kickin and correct it.
>
> In general, this patch also makes sense with out recent Nick's fixes
> in -mm.
>

Yeah, this makes sense. We may want to add some other criteria on the
removal of a domain as well (because some of the domain flags do things
that don't use groups).

I don't like so much that we'd rely on it to fix the above problem.
There are a general class of problems with the fork/exec balancing in
that it only works on the top most domain, so it may not spread load over
lower domains very well.

I was thinking we could fix that by running balance on fork/exec multiple
times from top to bottom level domains. I'll have to measure the cost of
doing that, because it may be worthwhile.

Thanks

--
SUSE Labs, Novell Inc.


-
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: 2005-04-06 13:31    [W:0.037 / U:0.388 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site