[PATCH] Fix relax_domain_level interface

[Dimitri Sivanich]

On Tue, Jun 05, 2012 at 08:36:59PM +0200, Peter Zijlstra wrote:
> On Tue, 2012-06-05 at 13:34 -0500, Dimitri Sivanich wrote:
> > 
> > I'll submit a patch shortly that should return these back to what appears to
> > be their intended functionality. 
> 
> I guess removing the max check in the paramater parsing is the easiest
> thing.
My thoughts exactly.



Fix the relax_domain_level boot parameter. It does not get processed because
sched_domain_level_max is 0 at the time that setup_relax_domain_level()
is run.  Simply accept the value as it is, as we don't know the value
of sched_domain_level_max until sched domain construction is completed.

Fix sched_relax_domain_level in cpuset.  The build_sched_domain() routine calls
the set_domain_attribute() routine prior to setting the sd->level, however,
the set_domain_attribute() routine relies on the sd->level to decide whether
idle load balancing will be off/on.

Signed-off-by: Dimitri Sivanich <sivanich@xxxxxxx>
---
 kernel/sched/core.c |    9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

Index: linux/kernel/sched/core.c
===================================================================
--- linux.orig/kernel/sched/core.c
+++ linux/kernel/sched/core.c
@@ -6165,11 +6165,8 @@ int sched_domain_level_max;
 
 static int __init setup_relax_domain_level(char *str)
 {
-	unsigned long val;
-
-	val = simple_strtoul(str, NULL, 0);
-	if (val < sched_domain_level_max)
-		default_relax_domain_level = val;
+	if (kstrtoint(str, 0, &default_relax_domain_level))
+		pr_warn("Unable to set relax_domain_level\n");
 
 	return 1;
 }
@@ -6543,7 +6540,6 @@ struct sched_domain *build_sched_domain(
 	if (!sd)
 		return child;
 
-	set_domain_attribute(sd, attr);
 	cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu));
 	if (child) {
 		sd->level = child->level + 1;
@@ -6551,6 +6547,7 @@ struct sched_domain *build_sched_domain(
 		child->parent = sd;
 	}
 	sd->child = child;
+	set_domain_attribute(sd, attr);
 
 	return sd;
 }
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