From 27415a4fe369e07a1393ae52c8ed8e48aabed5a9 Mon Sep 17 00:00:00 2001
From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Date: Wed, 30 Jan 2008 13:33:18 +0100
Subject: [PATCH] x86: move warning message of polling idle and HT enabled
The warning message at idle_setup() is never shown because
smp_num_sibling hasn't been updated at this point yet.
Move this polling idle and HT enabled warning to select_idle_routine().
I also implement this warning on 64-bit kernel.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/kernel/process_32.c | 18 ++++++++++++------
arch/x86/kernel/process_64.c | 17 ++++++++++++-----
2 files changed, 24 insertions(+), 11 deletions(-)
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 9f45a51af968b..b72d7d132072f 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -295,17 +295,27 @@ static int mwait_usable(const struct cpuinfo_x86 *c)
void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
{
+ static int selected;
+
+ if (selected)
+ return;
+#ifdef CONFIG_X86_SMP
+ if (pm_idle == poll_idle && smp_num_siblings > 1) {
+ printk(KERN_WARNING "WARNING: polling idle and HT enabled,"
+ " performance may degrade.\n");
+ }
+#endif
if (cpu_has(c, X86_FEATURE_MWAIT) && mwait_usable(c)) {
- printk("monitor/mwait feature present.\n");
/*
* Skip, if setup has overridden idle.
* One CPU supports mwait => All CPUs supports mwait
*/
if (!pm_idle) {
- printk("using mwait in idle threads.\n");
+ printk(KERN_INFO "using mwait in idle threads.\n");
pm_idle = mwait_idle;
}
}
+ selected = 1;
}
static int __init idle_setup(char *str)
@@ -313,10 +323,6 @@ static int __init idle_setup(char *str)
if (!strcmp(str, "poll")) {
printk("using polling idle threads.\n");
pm_idle = poll_idle;
-#ifdef CONFIG_X86_SMP
- if (smp_num_siblings > 1)
- printk("WARNING: polling idle and HT enabled, performance may degrade.\n");
-#endif
} else if (!strcmp(str, "mwait"))
force_mwait = 1;
else
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index dbe0a846ec52a..95313532b2e0f 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -291,20 +291,27 @@ static int mwait_usable(const struct cpuinfo_x86 *c)
void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
{
- static int printed;
+ static int selected;
+
+ if (selected)
+ return;
+#ifdef CONFIG_X86_SMP
+ if (pm_idle == poll_idle && smp_num_siblings > 1) {
+ printk(KERN_WARNING "WARNING: polling idle and HT enabled,"
+ " performance may degrade.\n");
+ }
+#endif
if (cpu_has(c, X86_FEATURE_MWAIT) && mwait_usable(c)) {
/*
* Skip, if setup has overridden idle.
* One CPU supports mwait => All CPUs supports mwait
*/
if (!pm_idle) {
- if (!printed) {
- printk(KERN_INFO "using mwait in idle threads.\n");
- printed = 1;
- }
+ printk(KERN_INFO "using mwait in idle threads.\n");
pm_idle = mwait_idle;
}
}
+ selected = 1;
}
static int __init idle_setup(char *str)
--
2.39.5