diff options
Diffstat (limited to 'arch/ia64/kernel')
| -rw-r--r-- | arch/ia64/kernel/time.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c index 6c0e9e2e1b8..98cfc90cab1 100644 --- a/arch/ia64/kernel/time.c +++ b/arch/ia64/kernel/time.c @@ -240,7 +240,21 @@ ia64_init_itm (void) 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(); |