From: Dominik Brodowski 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. The time is being measured in PM timer ticks, so an increase by one equals 279 nanoseconds. Signed-off-by: Dominik Brodowski Cc: Signed-off-by: Andrew Morton --- drivers/acpi/processor_idle.c | 10 ++++++---- include/acpi/processor.h | 1 + 2 files changed, 7 insertions(+), 4 deletions(-) diff -puN drivers/acpi/processor_idle.c~acpi-c-states-accounting-of-sleep-states drivers/acpi/processor_idle.c --- a/drivers/acpi/processor_idle.c~acpi-c-states-accounting-of-sleep-states +++ a/drivers/acpi/processor_idle.c @@ -325,8 +325,6 @@ static void acpi_processor_idle(void) cx = &pr->power.states[ACPI_STATE_C1]; #endif - cx->usage++; - /* * Sleep: * ------ @@ -424,6 +422,9 @@ 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; @@ -1058,9 +1059,10 @@ 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: diff -puN include/acpi/processor.h~acpi-c-states-accounting-of-sleep-states include/acpi/processor.h --- a/include/acpi/processor.h~acpi-c-states-accounting-of-sleep-states +++ a/include/acpi/processor.h @@ -62,6 +62,7 @@ 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; }; _