Also track the actual time spent in C-States (C2 upwards, we can't determine this for C1), not only the number of invocations. This is especially useful for dynamic ticks / "tickless systems", but is also of interest on normal systems, as any interrupt activity leads to C-States being exited, not only the timer interrupt. Signed-off-by: Dominik Brodowski drivers/acpi/processor_idle.c | 10 ++++++---- include/acpi/processor.h | 1 + 2 files changed, 7 insertions(+), 4 deletions(-) Index: linux-2.6.16-rc5-dt/drivers/acpi/processor_idle.c =================================================================== --- linux-2.6.16-rc5-dt.orig/drivers/acpi/processor_idle.c 2006-02-27 20:32:59.000000000 +1100 +++ linux-2.6.16-rc5-dt/drivers/acpi/processor_idle.c 2006-02-27 20:32:59.000000000 +1100 @@ -317,8 +317,6 @@ static void acpi_processor_idle(void) cx = &pr->power.states[ACPI_STATE_C1]; #endif - cx->usage++; - /* * Sleep: * ------ @@ -416,6 +414,9 @@ static void acpi_processor_idle(void) local_irq_enable(); return; } + cx->usage++; + if ((cx->type != ACPI_STATE_C1) && (sleep_ticks > 0)) + cx->time += sleep_ticks; next_state = pr->power.state; @@ -1043,9 +1044,10 @@ static int acpi_processor_power_seq_show else seq_puts(seq, "demotion[--] "); - seq_printf(seq, "latency[%03d] usage[%08d]\n", + seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n", pr->power.states[i].latency, - pr->power.states[i].usage); + pr->power.states[i].usage, + pr->power.states[i].time); } end: Index: linux-2.6.16-rc5-dt/include/acpi/processor.h =================================================================== --- linux-2.6.16-rc5-dt.orig/include/acpi/processor.h 2006-02-27 16:40:23.000000000 +1100 +++ linux-2.6.16-rc5-dt/include/acpi/processor.h 2006-02-27 20:32:59.000000000 +1100 @@ -51,6 +51,7 @@ struct acpi_processor_cx { u32 latency_ticks; u32 power; u32 usage; + u64 time; struct acpi_processor_cx_policy promotion; struct acpi_processor_cx_policy demotion; };