[PATCH 1/2] x86: move warning message of polling idle and HT enabled
From: Hiroshi Shimamoto
Date: Tue Jan 15 2008 - 13:59:56 EST
From: Hiroshi Shimamoto <h-shimamoto@xxxxxxxxxxxxx>
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@xxxxxxxxxxxxx>
---
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 69a69c3..d52c032 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -287,17 +287,27 @@ static void mwait_idle(void)
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)) {
- 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)
@@ -305,10 +315,6 @@ 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 5e12edd..8cff606 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -282,20 +282,27 @@ static void mwait_idle(void)
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)) {
/*
* 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)
--
1.5.3.6
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