[ 15/69] sched: Fix the relax_domain_level boot parameter

From: Ben Hutchings
Date: Sun Jun 17 2012 - 14:30:37 EST


3.2-stable review patch. If anyone has any objections, please let me know.

------------------

From: Dimitri Sivanich <sivanich@xxxxxxx>

commit a841f8cef4bb124f0f5563314d0beaf2e1249d72 upstream.

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>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Link: http://lkml.kernel.org/r/20120605184436.GA15668@xxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
[bwh: Backported to 3.2: adjust the filename]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
kernel/sched/core.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -7429,11 +7429,8 @@

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;
}
@@ -7636,7 +7633,6 @@
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;
@@ -7644,6 +7640,7 @@
child->parent = sd;
}
sd->child = child;
+ set_domain_attribute(sd, attr);

return sd;
}


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