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authorjohn stultz <johnstul@us.ibm.com>2007-05-02 19:27:08 +0200
committerAndi Kleen <andi@basil.nowhere.org>2007-05-02 19:27:08 +0200
commit5a90cf205c922707ffed2d8f87cefd942e96b0ba (patch)
tree5e9c9c1be3d149bff7620db89e1ede2317ba7362 /arch/x86_64
parent2714221985ce6388ec2fa78d7d52e2a5bef78eec (diff)
[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>
Diffstat (limited to 'arch/x86_64')
-rw-r--r--arch/x86_64/kernel/time.c2
-rw-r--r--arch/x86_64/kernel/tsc.c5
-rw-r--r--arch/x86_64/kernel/tsc_sync.c2
3 files changed, 5 insertions, 4 deletions
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index 5f862e216a4..91c9066a380 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -397,7 +397,7 @@ void __init time_init(void)
cpu_khz = tsc_calibrate_cpu_khz();
if (unsynchronized_tsc())
- mark_tsc_unstable();
+ mark_tsc_unstable("TSCs unsynchronized");
if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP))
vgetcpu_mode = VGETCPU_RDTSCP;
diff --git a/arch/x86_64/kernel/tsc.c b/arch/x86_64/kernel/tsc.c
index 5c84992c676..48f9a8e6aa9 100644
--- a/arch/x86_64/kernel/tsc.c
+++ b/arch/x86_64/kernel/tsc.c
@@ -111,7 +111,7 @@ static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
tsc_khz = cpufreq_scale(tsc_khz_ref, ref_freq, freq->new);
if (!(freq->flags & CPUFREQ_CONST_LOOPS))
- mark_tsc_unstable();
+ mark_tsc_unstable("cpufreq changes");
}
set_cyc2ns_scale(tsc_khz_ref);
@@ -199,10 +199,11 @@ static struct clocksource clocksource_tsc = {
.vread = vread_tsc,
};
-void mark_tsc_unstable(void)
+void mark_tsc_unstable(char *reason)
{
if (!tsc_unstable) {
tsc_unstable = 1;
+ printk("Marking TSC unstable due to %s\n", reason);
/* Change only the rating, when not registered */
if (clocksource_tsc.mult)
clocksource_change_rating(&clocksource_tsc, 0);
diff --git a/arch/x86_64/kernel/tsc_sync.c b/arch/x86_64/kernel/tsc_sync.c
index 72d444dede9..355f5f506c8 100644
--- a/arch/x86_64/kernel/tsc_sync.c
+++ b/arch/x86_64/kernel/tsc_sync.c
@@ -138,7 +138,7 @@ void __cpuinit check_tsc_sync_source(int cpu)
printk("\n");
printk(KERN_WARNING "Measured %Ld cycles TSC warp between CPUs,"
" turning off TSC clock.\n", max_warp);
- mark_tsc_unstable();
+ mark_tsc_unstable("check_tsc_sync_source failed");
nr_warps = 0;
max_warp = 0;
last_tsc = 0;