admin/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2025-12-07 20:06:24 +00:00
Code Issues Packages Projects Releases Wiki Activity

ACPI: processor: Rescan "dead" SMT siblings during initialization

Browse Source 
Make acpi_processor_driver_init() call arch_cpu_rescan_dead_smt_siblings(),
via a new wrapper function called acpi_idle_rescan_dead_smt_siblings(),
after successfully initializing the driver, to allow the "dead" SMT
siblings to go into deep idle states, which is necessary for the
processor to be able to reach deep package C-states (like PC10) going
forward, so that power can be reduced sufficiently in suspend-to-idle,
among other things.

However, do it only if the ACPI idle driver is the current cpuidle
driver (otherwise it is assumed that another cpuidle driver will take
care of this) and avoid doing it on architectures other than x86.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Link: https://patch.msgid.link/2005721.PYKUYFuaPT@rjwysocki.net
This commit is contained in:
Rafael J. Wysocki
2025-06-05 17:07:31 +02:00
parent a430c11f40
commit f694481b1d
3 changed files with 17 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/acpi/internal.h
View File

@@ -175,6 +175,12 @@ bool processor_physically_present(acpi_handle handle);
static inline void acpi_early_processor_control_setup(void) {}
#endif
#ifdef CONFIG_ACPI_PROCESSOR_CSTATE
void acpi_idle_rescan_dead_smt_siblings(void);
#else
static inline void acpi_idle_rescan_dead_smt_siblings(void) {}
#endif
/* --------------------------------------------------------------------------
Embedded Controller
-------------------------------------------------------------------------- */

3
drivers/acpi/processor_driver.c
View File

@@ -279,6 +279,9 @@ static int __init acpi_processor_driver_init(void)
* after acpi_cppc_processor_probe() has been called for all online CPUs
*/
acpi_processor_init_invariance_cppc();
acpi_idle_rescan_dead_smt_siblings();
return 0;
err:
driver_unregister(&acpi_processor_driver);

8
drivers/acpi/processor_idle.c
View File

@@ -24,6 +24,8 @@
#include <acpi/processor.h>
#include <linux/context_tracking.h>
#include "internal.h"
/*
* Include the apic definitions for x86 to have the APIC timer related defines
* available also for UP (on SMP it gets magically included via linux/smp.h).
@@ -55,6 +57,12 @@ struct cpuidle_driver acpi_idle_driver = {
};
#ifdef CONFIG_ACPI_PROCESSOR_CSTATE
void acpi_idle_rescan_dead_smt_siblings(void)
{
if (cpuidle_get_driver() == &acpi_idle_driver)
arch_cpu_rescan_dead_smt_siblings();
}
static
DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);