lkml.org 
[lkml]   [2006]   [Feb]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 1/5] cpuset memory spread basic implementation

* Paul Jackson <pj@sgi.com> wrote:

> Ingo asked:
> > so in practice, the memory spreading is in fact a global setting, used
> > by all cpusets that matter?
>
> I don't know if that is true or not.
>
> I'll have to ask my field engineers, who actually have experience
> with a variety of customer workloads.
>
> ... well, I do have partial knowledge of this.
>
> When I was coding this, I suggested that instead of picking some of the
> slab caches to memory spread, we pick them all, as that would be easier
> to code.
>
> That suggestion was shot down by others more experienced within SGI,
> as some slab caches hold what is essentially per-thread data, that is
> fairly hot in the thread context that allocated it. Spreading that
> data would quite predictably increase cross-node bus traffic, which is
> bad.

yes, but still that is a global attribute: we know that those slabs are
fundamentally per-thread. They wont ever be non-per-thread. So the
decision could be made via a per-slab attribute, that is picked by
kernel developers (initially you). The pagecache would be spread-out if
this .config option is specified. This makes it a much cleaner static
'kernel fairness policy' thing, instead of a fuzzier userspace thing.

Ingo
-
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: 2006-02-06 09:55    [W:0.211 / U:0.092 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site