diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index ca89e15..0578fcb 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -54,6 +54,7 @@ static LIST_HEAD(clocksource_list); static DEFINE_SPINLOCK(clocksource_lock); static char override_name[32]; static int finished_booting; +static int force_tsc_stable; /* clocksource_done_booting - Called near the end of core bootup * @@ -82,6 +83,14 @@ static unsigned long watchdog_resumed; #define WATCHDOG_INTERVAL (HZ >> 1) #define WATCHDOG_THRESHOLD (NSEC_PER_SEC >> 4) +static int __init parse_force_tsc_stable(char *arg) +{ + force_tsc_stable = 1; + return 0; +} +early_param("force_tsc_stable", parse_force_tsc_stable); + + static void clocksource_ratewd(struct clocksource *cs, int64_t delta) { if (delta > -WATCHDOG_THRESHOLD && delta < WATCHDOG_THRESHOLD) @@ -89,9 +98,16 @@ static void clocksource_ratewd(struct clocksource *cs, int64_t delta) printk(KERN_WARNING "Clocksource %s unstable (delta = %Ld ns)\n", cs->name, delta); - cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG); - clocksource_change_rating(cs, 0); - list_del(&cs->wd_list); + if (force_tsc_stable && (strcmp(cs->name, "tsc") == 0)) + printk(KERN_WARNING "Forcing tsc to be treated as stable due to force_tsc_stable=1\n"); + else { + printk(KERN_WARNING " This clock is no longer valid for WATCHDOG or HIGH-RES.\n"); + if (strcmp(cs->name, "tsc") == 0) + printk(KERN_WARNING " Use force_tsc_stable=1 to override.\n"); + cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG); + clocksource_change_rating(cs, 0); + list_del(&cs->wd_list); + } } static void clocksource_watchdog(unsigned long data)