/*
- * arch/x86_64/kernel/tsc_sync.c: check TSC synchronization.
+ * check TSC synchronization.
*
* Copyright (C) 2006, Red Hat, Inc., Ingo Molnar
*
cycles_t start, now, prev, end;
int i;
- start = get_cycles_sync();
+ start = get_cycles();
/*
* The measurement runs for 20 msecs:
*/
*/
__raw_spin_lock(&sync_lock);
prev = last_tsc;
- now = get_cycles_sync();
+ now = get_cycles();
last_tsc = now;
__raw_spin_unlock(&sync_lock);
/*
* Be nice every now and then (and also check whether
- * measurement is done [we also insert a 100 million
+ * measurement is done [we also insert a 10 million
* loops safety exit, so we dont lock up in case the
* TSC readout is totally broken]):
*/
if (unlikely(!(i & 7))) {
- if (now > end || i > 100000000)
+ if (now > end || i > 10000000)
break;
cpu_relax();
touch_nmi_watchdog();
nr_warps++;
__raw_spin_unlock(&sync_lock);
}
-
+ }
+ if (!(now-start)) {
+ printk("Warning: zero tsc calibration delta: %Ld [max: %Ld]\n",
+ now-start, end-start);
+ WARN_ON(1);
}
}
while (atomic_read(&stop_count) != cpus-1)
cpu_relax();
- /*
- * Reset it - just in case we boot another CPU later:
- */
- atomic_set(&start_count, 0);
-
if (nr_warps) {
printk("\n");
printk(KERN_WARNING "Measured %Ld cycles TSC warp between CPUs,"
" turning off TSC clock.\n", max_warp);
mark_tsc_unstable("check_tsc_sync_source failed");
- nr_warps = 0;
- max_warp = 0;
- last_tsc = 0;
} else {
printk(" passed.\n");
}
+ /*
+ * Reset it - just in case we boot another CPU later:
+ */
+ atomic_set(&start_count, 0);
+ nr_warps = 0;
+ max_warp = 0;
+ last_tsc = 0;
+
/*
* Let the target continue with the bootup:
*/