lkml.org 
[lkml]   [2006]   [Feb]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: calibrate_migration_costs takes ages on s390
 On Mon, Feb 13, Ingo Molnar wrote:

>
> * Heiko Carstens <heiko.carstens@de.ibm.com> wrote:
>
> > The boot sequence on s390 sometimes takes ages and we spend a very
> > long time (up to one or two minutes) in calibrate_migration_costs. The
> > time spent there differs from boot to boot. Also the calculated costs
> > differ a lot. I've seen differences by up to a factor of 15 (yes,
> > factor not percent). Also I doubt that making these measurements make
> > much sense on a completely virtualized architecture where you cannot
> > tell how much cpu time you will get anyway. Is there any workaround or
> > fix available so we can avoid seeing this?
>
> which is the precise kernel version used? We toned down calibration a
> bit recently.

We did a bit of testing, -rc2-git3 + the patch below was still ok.

[PATCH] s390: earlier initialization of cpu_possible_map
9733e2407ad2237867cb13c04e7d619397fa3090

-
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: 2006-02-14 00:45    [W:0.082 / U:4.368 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site