[1/4] ACPI C-States: accounting of sleep states

Dominik Brodowski
2006-06-19T21:36:25Z

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 <linux@dominikbrodowski.net>

---

drivers/acpi/processor_idle.c | 10 ++++++----
include/acpi/processor.h | 1 +
2 files changed, 7 insertions(+), 4 deletions(-)

3997a08ff5aa0553dfff81801c3690a5c91ac7bc
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 80fa434..4f166fa 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -322,8 +322,6 @@ static void acpi_processor_idle(void)
cx = &pr->power.states[ACPI_STATE_C1];
#endif

- cx->usage++;
-
/*
* Sleep:
* ------
@@ -421,6 +419,9 @@ 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;

@@ -1055,9 +1056,10 @@ 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 --git a/include/acpi/processor.h b/include/acpi/processor.h
index badf027..ca0e031 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -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;
};
--
1.2.4