diff options
Diffstat (limited to 'arch/x86/kernel/tsc.c')
| -rw-r--r-- | arch/x86/kernel/tsc.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index f95603842..7437b41f6 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -12,7 +12,6 @@ #include <linux/percpu.h> #include <linux/timex.h> #include <linux/static_key.h> -#include <linux/mm.h> #include <asm/hpet.h> #include <asm/timer.h> @@ -196,10 +195,6 @@ static void cyc2ns_init(int cpu) c2n->head = c2n->data; c2n->tail = c2n->data; - - // Don't let TuxOnIce make data RO - a secondary CPU will cause a triple fault - // if it loads microcode, which then does a printk, which may end up invoking cycles_2_ns - SetPageTOI_Untracked(virt_to_page(c2n)); } static inline unsigned long long cycles_2_ns(unsigned long long cyc) @@ -603,10 +598,19 @@ static unsigned long quick_pit_calibrate(void) if (!pit_expect_msb(0xff-i, &delta, &d2)) break; + delta -= tsc; + + /* + * Extrapolate the error and fail fast if the error will + * never be below 500 ppm. + */ + if (i == 1 && + d1 + d2 >= (delta * MAX_QUICK_PIT_ITERATIONS) >> 11) + return 0; + /* * Iterate until the error is less than 500 ppm */ - delta -= tsc; if (d1+d2 >= delta >> 11) continue; |