From f6630114d9198aa959ac95c131334c020038f253 Mon Sep 17 00:00:00 2001
From: Mike Travis <travis@sgi.com>
Date: Tue, 17 Nov 2009 18:22:15 -0600
Subject: [PATCH] sched: Limit the number of scheduler debug messages
Remove the verbose scheduler debug messages unless kernel
parameter "sched_debug" set. /proc/sched_debug unchanged.
Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091118002221.489305000@alcatraz.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
Documentation/kernel-parameters.txt | 2 ++
kernel/sched.c | 13 +++++++++++++
2 files changed, 15 insertions(+)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 9107b387e91fc..f2a9507b27b2c 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2182,6 +2182,8 @@ and is between 256 and 4096 characters. It is defined in the file
sbni= [NET] Granch SBNI12 leased line adapter
+ sched_debug [KNL] Enables verbose scheduler debug messages.
+
sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
Format: <io>[,<timeout>[,<isapnp>]]
diff --git a/kernel/sched.c b/kernel/sched.c
index a57c6aee6d4ab..48ff66a6892d4 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -7720,6 +7720,16 @@ early_initcall(migration_init);
#ifdef CONFIG_SCHED_DEBUG
+static __read_mostly int sched_domain_debug_enabled;
+
+static int __init sched_domain_debug_setup(char *str)
+{
+ sched_domain_debug_enabled = 1;
+
+ return 0;
+}
+early_param("sched_debug", sched_domain_debug_setup);
+
static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
struct cpumask *groupmask)
{
@@ -7806,6 +7816,9 @@ static void sched_domain_debug(struct sched_domain *sd, int cpu)
cpumask_var_t groupmask;
int level = 0;
+ if (!sched_domain_debug_enabled)
+ return;
+
if (!sd) {
printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu);
return;
--
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