From 5a344a505093dd65f82f338ffdb7208321b3630e Mon Sep 17 00:00:00 2001 From: Zhao Yakui Date: Mon, 10 Jan 2011 16:35:45 +0800 Subject: ACPI: Reevaluate whether the T-state is supported or not after cpu is online/offline After one CPU is offlined, it is unnecessary to switch T-state for it. So it will be better that the throttling is disabled after the cpu is offline. At the same time after one cpu is online, we should check whether the T-state is supported and then set the corresponding T-state flag. Signed-off-by: Zhao Yakui Signed-off-by: Len Brown --- drivers/acpi/processor_driver.c | 5 ++++ drivers/acpi/processor_throttling.c | 52 +++++++++++++++++++++++++++++++++++++ 2 files changed, 57 insertions(+) (limited to 'drivers/acpi') diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c index 85e48047d7b0..c8a0ca2af839 100644 --- a/drivers/acpi/processor_driver.c +++ b/drivers/acpi/processor_driver.c @@ -478,8 +478,13 @@ static int acpi_cpu_soft_notify(struct notifier_block *nfb, if (action == CPU_ONLINE && pr) { acpi_processor_ppc_has_changed(pr, 0); acpi_processor_cst_has_changed(pr); + acpi_processor_reevaluate_tstate(pr, action); acpi_processor_tstate_has_changed(pr); } + if (action == CPU_DEAD && pr) { + /* invalidate the flag.throttling after one CPU is offline */ + acpi_processor_reevaluate_tstate(pr, action); + } return NOTIFY_OK; } diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c index ffc859c61393..4305d560b065 100644 --- a/drivers/acpi/processor_throttling.c +++ b/drivers/acpi/processor_throttling.c @@ -369,6 +369,58 @@ int acpi_processor_tstate_has_changed(struct acpi_processor *pr) return acpi_processor_set_throttling(pr, target_state, false); } +/* + * This function is used to reevaluate whether the T-state is valid + * after one CPU is onlined/offlined. + * It is noted that it won't reevaluate the following properties for + * the T-state. + * 1. Control method. + * 2. the number of supported T-state + * 3. TSD domain + */ +void acpi_processor_reevaluate_tstate(struct acpi_processor *pr, + unsigned long action) +{ + int result = 0; + + if (action == CPU_DEAD) { + /* When one CPU is offline, the T-state throttling + * will be invalidated. + */ + pr->flags.throttling = 0; + return; + } + /* the following is to recheck whether the T-state is valid for + * the online CPU + */ + if (!pr->throttling.state_count) { + /* If the number of T-state is invalid, it is + * invalidated. + */ + pr->flags.throttling = 0; + return; + } + pr->flags.throttling = 1; + + /* Disable throttling (if enabled). We'll let subsequent + * policy (e.g.thermal) decide to lower performance if it + * so chooses, but for now we'll crank up the speed. + */ + + result = acpi_processor_get_throttling(pr); + if (result) + goto end; + + if (pr->throttling.state) { + result = acpi_processor_set_throttling(pr, 0, false); + if (result) + goto end; + } + +end: + if (result) + pr->flags.throttling = 0; +} /* * _PTC - Processor Throttling Control (and status) register location */ -- cgit v1.2.3