diff options
| author | Zachary Amsden <zach@vmware.com> | 2007-03-05 00:30:36 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-03-05 07:57:52 -0800 |
| commit | 1182d8528b620c23d043bccbbef092b42062960a (patch) | |
| tree | 3df690a1a731811f8fecda06cb785a5a7b06d4d0 /arch/i386/kernel | |
| parent | 6cb9a8350aee789100a365794272ed20cc8f2401 (diff) | |
[PATCH] vmi: cpu cycles fix
In order to share the common code in tsc.c which does CPU Khz calibration, we
need to make an accurate value of CPU speed available to the tsc.c code. This
value loses a lot of precision in a VM because of the timing differences with
real hardware, but we need it to be as precise as possible so the guest can
make accurate time calculations with the cycle counters.
Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/i386/kernel')
| -rw-r--r-- | arch/i386/kernel/paravirt.c | 1 | ||||
| -rw-r--r-- | arch/i386/kernel/tsc.c | 2 | ||||
| -rw-r--r-- | arch/i386/kernel/vmi.c | 1 | ||||
| -rw-r--r-- | arch/i386/kernel/vmitime.c | 10 |
4 files changed, 12 insertions, 2 deletions
diff --git a/arch/i386/kernel/paravirt.c b/arch/i386/kernel/paravirt.c index 31bbe70d1e0..8352394d5ef 100644 --- a/arch/i386/kernel/paravirt.c +++ b/arch/i386/kernel/paravirt.c @@ -522,6 +522,7 @@ struct paravirt_ops paravirt_ops = { .read_tsc = native_read_tsc, .read_pmc = native_read_pmc, .get_scheduled_cycles = native_read_tsc, + .get_cpu_khz = native_calculate_cpu_khz, .load_tr_desc = native_load_tr_desc, .set_ldt = native_set_ldt, .load_gdt = native_load_gdt, diff --git a/arch/i386/kernel/tsc.c b/arch/i386/kernel/tsc.c index c9c9d54c91f..59222a04234 100644 --- a/arch/i386/kernel/tsc.c +++ b/arch/i386/kernel/tsc.c @@ -117,7 +117,7 @@ unsigned long long sched_clock(void) return cycles_2_ns(this_offset); } -static unsigned long calculate_cpu_khz(void) +unsigned long native_calculate_cpu_khz(void) { unsigned long long start, end; unsigned long count; diff --git a/arch/i386/kernel/vmi.c b/arch/i386/kernel/vmi.c index 556b9a6b736..acdfe69fb7a 100644 --- a/arch/i386/kernel/vmi.c +++ b/arch/i386/kernel/vmi.c @@ -874,6 +874,7 @@ static inline int __init activate_vmi(void) paravirt_ops.setup_secondary_clock = vmi_timer_setup_secondary_alarm; #endif paravirt_ops.get_scheduled_cycles = vmi_get_sched_cycles; + paravirt_ops.get_cpu_khz = vmi_cpu_khz; } if (!disable_noidle) para_fill(safe_halt, Halt); diff --git a/arch/i386/kernel/vmitime.c b/arch/i386/kernel/vmitime.c index f2aa8fab8c0..4bb218e2eb1 100644 --- a/arch/i386/kernel/vmitime.c +++ b/arch/i386/kernel/vmitime.c @@ -177,6 +177,15 @@ unsigned long long vmi_get_sched_cycles(void) return read_available_cycles(); } +unsigned long vmi_cpu_khz(void) +{ + unsigned long long khz; + + khz = vmi_timer_ops.get_cycle_frequency(); + (void)do_div(khz, 1000); + return khz; +} + void __init vmi_time_init(void) { unsigned long long cycles_per_sec, cycles_per_msec; @@ -206,7 +215,6 @@ void __init vmi_time_init(void) (void)do_div(cycles_per_alarm, alarm_hz); cycles_per_msec = cycles_per_sec; (void)do_div(cycles_per_msec, 1000); - cpu_khz = cycles_per_msec; printk(KERN_WARNING "VMI timer cycles/sec = %llu ; cycles/jiffy = %llu ;" "cycles/alarm = %llu\n", cycles_per_sec, cycles_per_jiffy, |