[PATCH] x86: Log reason why TSC was marked unstable

Change mark_tsc_unstable() so it takes a string argument, which holds the
reason the TSC was marked unstable.

This is then displayed the first time mark_tsc_unstable is called.

This should help us better debug why the TSC was marked unstable on certain
systems and allow us to make sure we're not being overly paranoid when
throwing out this troublesome clocksource.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andi Kleen <ak@suse.de>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index ae0654cd11ea..ee5759bef945 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -475,7 +475,7 @@ static void acpi_processor_idle(void)
 
 #ifdef CONFIG_GENERIC_TIME
                 /* TSC halts in C2, so notify users */
-                mark_tsc_unstable();
+                mark_tsc_unstable("possible TSC halt in C2");
 #endif
                 /* Re-enable interrupts */
                 local_irq_enable();
@@ -517,7 +517,7 @@ static void acpi_processor_idle(void)
 
 #ifdef CONFIG_GENERIC_TIME
                 /* TSC halts in C3, so notify users */
-                mark_tsc_unstable();
+                mark_tsc_unstable("TSC halts in C3");
 #endif
                 /* Re-enable interrupts */
                 local_irq_enable();