.name = "itc",
.rating = 350,
.read = itc_get_cycles,
- .mask = 0xffffffffffffffff,
+ .mask = CLOCKSOURCE_MASK(64),
.mult = 0, /*to be caluclated*/
.shift = 16,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
if (!nojitter)
itc_jitter_data.itc_jitter = 1;
#endif
- }
+ } else
+ /*
+ * ITC is drifty and we have not synchronized the ITCs in smpboot.c.
+ * ITC values may fluctuate significantly between processors.
+ * Clock should not be used for hrtimers. Mark itc as only
+ * useful for boot and testing.
+ *
+ * Note that jitter compensation is off! There is no point of
+ * synchronizing ITCs since they may be large differentials
+ * that change over time.
+ *
+ * The only way to fix this would be to repeatedly sync the
+ * ITCs. Until that time we have to avoid ITC.
+ */
+ clocksource_itc.rating = 50;
/* Setup the CPU local timer tick */
ia64_cpu_local_tick();
}
}
-static cycle_t itc_get_cycles()
+static cycle_t itc_get_cycles(void)
{
u64 lcycle, now, ret;