Merge branch 'misc' into release (ca62cf59) · Commits · 戴 / test

Documentation/kernel-parameters.txt

+1 −10

Original line number	Diff line number	Diff line
		@@ -1039,16 +1039,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
		Claim all unknown PCI IDE storage controllers.

		idle= [X86]
		Format: idle=poll, idle=mwait, idle=halt, idle=nomwait
		Format: idle=poll, idle=halt, idle=nomwait
		Poll forces a polling idle loop that can slightly
		improve the performance of waking up a idle CPU, but
		will use a lot of power and make the system run hot.
		Not recommended.
		idle=mwait: On systems which support MONITOR/MWAIT but
		the kernel chose 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.
		idle=nomwait: Disable mwait for CPU C-states
		@@ -1886,10 +1881,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
		wfi(ARM) instruction doesn't work correctly and not to
		use it. This is also useful when using JTAG debugger.

		no-hlt [BUGS=X86-32] Tells the kernel that the hlt
		instruction doesn't work correctly and not to
		use it.

		no_file_caps Tells the kernel not to honor file capabilities. The
		only way then for a file to be executed with privilege
		is to be setuid root or executed by root.

arch/x86/include/asm/processor.h

+6 −12

Original line number	Diff line number	Diff line
		@@ -89,7 +89,6 @@ struct cpuinfo_x86 {
		char wp_works_ok; /* It doesn't on 386's */

		/* Problems on some 486Dx4's and old 386's: */
		char hlt_works_ok;
		char hard_math;
		char rfu;
		char fdiv_bug;
		@@ -165,15 +164,6 @@ DECLARE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info);

		extern const struct seq_operations cpuinfo_op;

		static inline int hlt_works(int cpu)
		{
		#ifdef CONFIG_X86_32
		return cpu_data(cpu).hlt_works_ok;
		#else
		return 1;
		#endif
		}

		#define cache_line_size() (boot_cpu_data.x86_cache_alignment)

		extern void cpu_detect(struct cpuinfo_x86 *c);
		@@ -725,7 +715,7 @@ extern unsigned long boot_option_idle_override;
		extern bool amd_e400_c1e_detected;

		enum idle_boot_override {IDLE_NO_OVERRIDE=0, IDLE_HALT, IDLE_NOMWAIT,
		IDLE_POLL, IDLE_FORCE_MWAIT};
		IDLE_POLL};

		extern void enable_sep_cpu(void);
		extern int sysenter_setup(void);
		@@ -998,7 +988,11 @@ extern unsigned long arch_align_stack(unsigned long sp);
		extern void free_init_pages(char *what, unsigned long begin, unsigned long end);

		void default_idle(void);
		bool set_pm_idle_to_default(void);
		#ifdef CONFIG_XEN
		bool xen_set_default_idle(void);
		#else
		#define xen_set_default_idle 0
		#endif

		void stop_this_cpu(void *dummy);

arch/x86/kernel/cpu/bugs.c

+0 −27

Original line number	Diff line number	Diff line
		@@ -17,15 +17,6 @@
		#include <asm/paravirt.h>
		#include <asm/alternative.h>

		static int __init no_halt(char *s)
		{
		WARN_ONCE(1, "\"no-hlt\" is deprecated, please use \"idle=poll\"\n");
		boot_cpu_data.hlt_works_ok = 0;
		return 1;
		}

		__setup("no-hlt", no_halt);

		static int __init no_387(char *s)
		{
		boot_cpu_data.hard_math = 0;
		@@ -89,23 +80,6 @@ static void __init check_fpu(void)
		pr_warn("Hmm, FPU with FDIV bug\n");
		}

		static void __init check_hlt(void)
		{
		if (boot_cpu_data.x86 >= 5 \|\| paravirt_enabled())
		return;

		pr_info("Checking 'hlt' instruction... ");
		if (!boot_cpu_data.hlt_works_ok) {
		pr_cont("disabled\n");
		return;
		}
		halt();
		halt();
		halt();
		halt();
		pr_cont("OK\n");
		}

		/*
		* Check whether we are able to run this kernel safely on SMP.
		*
		@@ -129,7 +103,6 @@ void __init check_bugs(void)
		print_cpu_info(&boot_cpu_data);
		#endif
		check_config();
		check_hlt();
		init_utsname()->machine[1] =
		'0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86);
		alternative_instructions();

arch/x86/kernel/cpu/proc.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -28,7 +28,6 @@ static void show_cpuinfo_misc(struct seq_file m, struct cpuinfo_x86 c)
		{
		seq_printf(m,
		"fdiv_bug\t: %s\n"
		"hlt_bug\t\t: %s\n"
		"f00f_bug\t: %s\n"
		"coma_bug\t: %s\n"
		"fpu\t\t: %s\n"
		@@ -36,7 +35,6 @@ static void show_cpuinfo_misc(struct seq_file m, struct cpuinfo_x86 c)
		"cpuid level\t: %d\n"
		"wp\t\t: %s\n",
		c->fdiv_bug ? "yes" : "no",
		c->hlt_works_ok ? "no" : "yes",
		c->f00f_bug ? "yes" : "no",
		c->coma_bug ? "yes" : "no",
		c->hard_math ? "yes" : "no",

arch/x86/kernel/process.c

+6 −83

Original line number	Diff line number	Diff line
		@@ -390,7 +390,8 @@ void default_idle(void)
		EXPORT_SYMBOL(default_idle);
		#endif

		bool set_pm_idle_to_default(void)
		#ifdef CONFIG_XEN
		bool xen_set_default_idle(void)
		{
		bool ret = !!x86_idle;

		@@ -398,6 +399,7 @@ bool set_pm_idle_to_default(void)

		return ret;
		}
		#endif
		void stop_this_cpu(void *dummy)
		{
		local_irq_disable();
		@@ -407,32 +409,9 @@ void stop_this_cpu(void *dummy)
		set_cpu_online(smp_processor_id(), false);
		disable_local_APIC();

		for (;;) {
		if (hlt_works(smp_processor_id()))
		for (;;)
		halt();
		}
		}

		/* Default MONITOR/MWAIT with no hints, used for default C1 state */
		static void mwait_idle(void)
		{
		if (!need_resched()) {
		trace_power_start_rcuidle(POWER_CSTATE, 1, smp_processor_id());
		trace_cpu_idle_rcuidle(1, smp_processor_id());
		if (this_cpu_has(X86_FEATURE_CLFLUSH_MONITOR))
		clflush((void *)&current_thread_info()->flags);

		__monitor((void *)&current_thread_info()->flags, 0, 0);
		smp_mb();
		if (!need_resched())
		__sti_mwait(0, 0);
		else
		local_irq_enable();
		trace_power_end_rcuidle(smp_processor_id());
		trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
		} else
		local_irq_enable();
		}

		/*
		* On SMP it's slightly faster (but much more power-consuming!)
		@@ -450,53 +429,6 @@ static void poll_idle(void)
		trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
		}

		/*
		* mwait selection logic:
		*
		* It depends on the CPU. For AMD CPUs that support MWAIT this is
		* wrong. Family 0x10 and 0x11 CPUs will enter C1 on HLT. Powersavings
		* then depend on a clock divisor and current Pstate of the core. If
		* all cores of a processor are in halt state (C1) the processor can
		* enter the C1E (C1 enhanced) state. If mwait is used this will never
		* happen.
		*
		* idle=mwait overrides this decision and forces the usage of mwait.
		*/

		#define MWAIT_INFO 0x05
		#define MWAIT_ECX_EXTENDED_INFO 0x01
		#define MWAIT_EDX_C1 0xf0

		int mwait_usable(const struct cpuinfo_x86 *c)
		{
		u32 eax, ebx, ecx, edx;

		/* Use mwait if idle=mwait boot option is given */
		if (boot_option_idle_override == IDLE_FORCE_MWAIT)
		return 1;

		/*
		* Any idle= boot option other than idle=mwait means that we must not
		* use mwait. Eg: idle=halt or idle=poll or idle=nomwait
		*/
		if (boot_option_idle_override != IDLE_NO_OVERRIDE)
		return 0;

		if (c->cpuid_level < MWAIT_INFO)
		return 0;

		cpuid(MWAIT_INFO, &eax, &ebx, &ecx, &edx);
		/* Check, whether EDX has extended info about MWAIT */
		if (!(ecx & MWAIT_ECX_EXTENDED_INFO))
		return 1;

		/*
		* edx enumeratios MONITOR/MWAIT extensions. Check, whether
		* C1 supports MWAIT
		*/
		return (edx & MWAIT_EDX_C1);
		}

		bool amd_e400_c1e_detected;
		EXPORT_SYMBOL(amd_e400_c1e_detected);

		@@ -567,13 +499,7 @@ void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
		if (x86_idle)
		return;

		if (cpu_has(c, X86_FEATURE_MWAIT) && mwait_usable(c)) {
		/*
		* One CPU supports mwait => All CPUs supports mwait
		*/
		pr_info("using mwait in idle threads\n");
		x86_idle = mwait_idle;
		} else if (cpu_has_amd_erratum(amd_erratum_400)) {
		if (cpu_has_amd_erratum(amd_erratum_400)) {
		/* E400: APIC timer interrupt does not wake up CPU from C1e */
		pr_info("using AMD E400 aware idle routine\n");
		x86_idle = amd_e400_idle;
		@@ -597,9 +523,6 @@ static int __init idle_setup(char *str)
		pr_info("using polling idle threads\n");
		x86_idle = poll_idle;
		boot_option_idle_override = IDLE_POLL;
		} else if (!strcmp(str, "mwait")) {
		boot_option_idle_override = IDLE_FORCE_MWAIT;
		WARN_ONCE(1, "\"idle=mwait\" will be removed in 2012\n");
		} else if (!strcmp(str, "halt")) {
		/*
		* When the boot option of idle=halt is added, halt is

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