ACPI: Create "idle=halt" bootparam (c1e3b377) · Commits · 戴 / test

Documentation/kernel-parameters.txt

+3 −1

Original line number	Diff line number	Diff line
		@@ -818,7 +818,7 @@ and is between 256 and 4096 characters. It is defined in the file
		See Documentation/ide/ide.txt.

		idle= [X86]
		Format: idle=poll or idle=mwait
		Format: idle=poll or idle=mwait, idle=halt
		Poll forces a polling idle loop that can slightly improves the performance
		of waking up a idle CPU, but will use a lot of power and make the system
		run hot. Not recommended.
		@@ -826,6 +826,8 @@ and is between 256 and 4096 characters. It is defined in the file
		to not use it because it doesn't save as much power as a normal idle
		loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same
		as idle=poll.
		idle=halt. Halt is forced to be used for CPU idle.
		In such case C2/C3 won't be used again.

		ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
		Claim all unknown PCI IDE storage controllers.

+2 −0

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		@@ -55,6 +55,8 @@ void (*ia64_mark_idle)(int);

		unsigned long boot_option_idle_override = 0;
		EXPORT_SYMBOL(boot_option_idle_override);
		unsigned long idle_halt;
		EXPORT_SYMBOL(idle_halt);

		void
		ia64_do_show_stack (struct unw_frame_info info, void arg)

+16 −1

Original line number	Diff line number	Diff line
		@@ -7,6 +7,10 @@
		#include <linux/module.h>
		#include <linux/pm.h>
		#include <linux/clockchips.h>
		#include <asm/system.h>

		unsigned long idle_halt;
		EXPORT_SYMBOL(idle_halt);

		struct kmem_cache *task_xstate_cachep;

		@@ -325,7 +329,18 @@ static int __init idle_setup(char *str)
		pm_idle = poll_idle;
		} else if (!strcmp(str, "mwait"))
		force_mwait = 1;
		else
		else if (!strcmp(str, "halt")) {
		/*
		* When the boot option of idle=halt is added, halt is
		* forced to be used for CPU idle. In such case CPU C2/C3
		* won't be used again.
		* To continue to load the CPU idle driver, don't touch
		* the boot_option_idle_override.
		*/
		pm_idle = default_idle;
		idle_halt = 1;
		return 0;
		} else
		return -1;

		boot_option_idle_override = 1;

+22 −0

Original line number	Diff line number	Diff line
		@@ -41,6 +41,7 @@
		#include <linux/pm_qos_params.h>
		#include <linux/clockchips.h>
		#include <linux/cpuidle.h>
		#include <linux/cpuidle.h>

		/*
		* Include the apic definitions for x86 to have the APIC timer related defines
		@@ -57,6 +58,7 @@

		#include <acpi/acpi_bus.h>
		#include <acpi/processor.h>
		#include <asm/processor.h>

		#define ACPI_PROCESSOR_COMPONENT 0x01000000
		#define ACPI_PROCESSOR_CLASS "processor"
		@@ -955,6 +957,17 @@ static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
		} else {
		continue;
		}
		if (cx.type == ACPI_STATE_C1 && idle_halt) {
		/*
		* In most cases the C1 space_id obtained from
		* _CST object is FIXED_HARDWARE access mode.
		* But when the option of idle=halt is added,
		* the entry_method type should be changed from
		* CSTATE_FFH to CSTATE_HALT.
		*/
		cx.entry_method = ACPI_CSTATE_HALT;
		snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
		}
		} else {
		snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
		cx.address);
		@@ -1780,6 +1793,15 @@ int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
		return 0;

		if (!first_run) {
		if (idle_halt) {
		/*
		* When the boot option of "idle=halt" is added, halt
		* is used for CPU IDLE.
		* In such case C2/C3 is meaningless. So the max_cstate
		* is set to one.
		*/
		max_cstate = 1;
		}
		dmi_check_system(processor_power_dmi_table);
		max_cstate = acpi_processor_cstate_check(max_cstate);
		if (max_cstate < ACPI_C_STATES_MAX)

+1 −0

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		@@ -763,6 +763,7 @@ prefetchw (const void *x)
		#define spin_lock_prefetch(x) prefetchw(x)

		extern unsigned long boot_option_idle_override;
		extern unsigned long idle_halt;

		#endif /* !__ASSEMBLY__ */