--- arch/x86/kernel/tsc.c

+++ arch/x86/kernel/tsc.c

@@ -104,10 +104,14 @@ int __init notsc_setup(char *str)

__setup("notsc", notsc_setup);

+static int no_sched_irq_time;

+

static int __init tsc_setup(char *str)

{

if (!strcmp(str, "reliable"))

tsc_clocksource_reliable = 1;

+ if (!strncmp(str, "noirqtime", 9))

+ no_sched_irq_time = 1;

return 1;

}

@@ -802,6 +806,7 @@ void mark_tsc_unstable(char *reason)

if (!tsc_unstable) {

tsc_unstable = 1;

sched_clock_stable = 0;

+ disable_sched_clock_irqtime();

printk(KERN_INFO "Marking TSC unstable due to %s\n", reason);

/* Change only the rating, when not registered */

if (clocksource_tsc.mult)

@@ -990,6 +995,9 @@ void __init tsc_init(void)

/* now allow native_sched_clock() to use rdtsc */

tsc_disabled = 0;

+ if (!no_sched_irq_time)

+ enable_sched_clock_irqtime();

+

lpj = ((u64)tsc_khz * 1000);

do_div(lpj, HZ);

lpj_fine = lpj;