Messages in this thread Patch in this message | | | Date | Thu, 24 Sep 2009 15:06:54 +0800 | Subject | [RFC PATCH] delete unnecessary wbinvd while entering C3 for Intel CPU | From | Luming Yu <> |
| |
Hi there,
I came across acpi_idle_enter_simple, noticed wbinvd is an unnecessary overhead for all Intel MP CPUs that support C3 share cache. And caches should not be flushed by software while entering C3 type state.
Please review. If make sense, please apply.
Ps. The patch is enclosed in attachment. The inlined one is c&p of it for reading.
Thanks, Luming
Signed-off-by: Yu Luming <luming.yu@intel.com>
processor_idle.c | 4 ---- 1 file changed, 4 deletions(-)
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 66393d5..4a2355b 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -894,10 +894,6 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev, * access HPET ! */ lapic_timer_state_broadcast(pr, cx, 1); - - if (cx->type == ACPI_STATE_C3) - ACPI_FLUSH_CPU_CACHE(); - kt1 = ktime_get_real(); /* Tell the scheduler that we are going deep-idle: */ sched_clock_idle_sleep_event();[unhandled content-type:application/octet-stream] | |