[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>

3 files changed, 4 insertions, 4 deletions

diff --git a/include/asm-i386/mach-summit/mach_mpparse.h b/include/asm-i386/mach-summit/mach_mpparse.h
index 94268399170d..c2520539d934 100644
--- a/include/asm-i386/mach-summit/mach_mpparse.h
+++ b/include/asm-i386/mach-summit/mach_mpparse.h
@@ -30,7 +30,7 @@ static inline int mps_oem_check(struct mp_config_table *mpc, char *oem,
                         (!strncmp(productid, "VIGIL SMP", 9) 
                          || !strncmp(productid, "EXA", 3)
                          || !strncmp(productid, "RUTHLESS SMP", 12))){
-                mark_tsc_unstable();
+                mark_tsc_unstable("Summit based system");
                 use_cyclone = 1; /*enable cyclone-timer*/
                 setup_summit();
                 return 1;
@@ -44,7 +44,7 @@ static inline int acpi_madt_oem_check(char *oem_id, char *oem_table_id)
         if (!strncmp(oem_id, "IBM", 3) &&
             (!strncmp(oem_table_id, "SERVIGIL", 8)
              || !strncmp(oem_table_id, "EXA", 3))){
-                mark_tsc_unstable();
+                mark_tsc_unstable("Summit based system");
                 use_cyclone = 1; /*enable cyclone-timer*/
                 setup_summit();
                 return 1;
diff --git a/include/asm-i386/tsc.h b/include/asm-i386/tsc.h
index 84016ff481b9..346976632e15 100644
--- a/include/asm-i386/tsc.h
+++ b/include/asm-i386/tsc.h
@@ -53,7 +53,7 @@ static __always_inline cycles_t get_cycles_sync(void)
 }
 
 extern void tsc_init(void);
-extern void mark_tsc_unstable(void);
+extern void mark_tsc_unstable(char *reason);
 extern int unsynchronized_tsc(void);
 extern void init_tsc_clocksource(void);
 
diff --git a/include/asm-x86_64/timex.h b/include/asm-x86_64/timex.h
index 8c6808a3fba4..f6527e1b6c1c 100644
--- a/include/asm-x86_64/timex.h
+++ b/include/asm-x86_64/timex.h
@@ -27,6 +27,6 @@ extern int read_current_timer(unsigned long *timer_value);
 #define NS_SCALE        10 /* 2^10, carefully chosen */
 #define US_SCALE        32 /* 2^32, arbitralrily chosen */
 
-extern void mark_tsc_unstable(void);
+extern void mark_tsc_unstable(char *msg);
 extern void set_cyc2ns_scale(unsigned long khz);
 #endif