diff options
author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2013-05-01 08:47:44 -0700 |
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committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2013-05-01 08:47:44 -0700 |
commit | bf61c8840efe60fd8f91446860b63338fb424158 (patch) | |
tree | 7a71832407a4f0d6346db773343f4c3ae2257b19 /arch/x86/kernel/process.c | |
parent | 5846115b30f3a881e542c8bfde59a699c1c13740 (diff) | |
parent | 0c6a61657da78098472fd0eb71cc01f2387fa1bb (diff) |
Merge branch 'next' into for-linus
Prepare first set of updates for 3.10 merge window.
Diffstat (limited to 'arch/x86/kernel/process.c')
-rw-r--r-- | arch/x86/kernel/process.c | 187 |
1 files changed, 29 insertions, 158 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index b644e1c765dc..14ae10031ff0 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -262,54 +262,13 @@ void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p, propagate_user_return_notify(prev_p, next_p); } -int sys_fork(struct pt_regs *regs) -{ - return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL); -} - -/* - * This is trivial, and on the face of it looks like it - * could equally well be done in user mode. - * - * Not so, for quite unobvious reasons - register pressure. - * In user mode vfork() cannot have a stack frame, and if - * done by calling the "clone()" system call directly, you - * do not have enough call-clobbered registers to hold all - * the information you need. - */ -int sys_vfork(struct pt_regs *regs) -{ - return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs, 0, - NULL, NULL); -} - -long -sys_clone(unsigned long clone_flags, unsigned long newsp, - void __user *parent_tid, void __user *child_tid, struct pt_regs *regs) -{ - if (!newsp) - newsp = regs->sp; - return do_fork(clone_flags, newsp, regs, 0, parent_tid, child_tid); -} - /* * Idle related variables and functions */ unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE; EXPORT_SYMBOL(boot_option_idle_override); -/* - * Powermanagement idle function, if any.. - */ -void (*pm_idle)(void); -#ifdef CONFIG_APM_MODULE -EXPORT_SYMBOL(pm_idle); -#endif - -static inline int hlt_use_halt(void) -{ - return 1; -} +static void (*x86_idle)(void); #ifndef CONFIG_SMP static inline void play_dead(void) @@ -386,7 +345,7 @@ void cpu_idle(void) rcu_idle_enter(); if (cpuidle_idle_call()) - pm_idle(); + x86_idle(); rcu_idle_exit(); start_critical_timings(); @@ -410,41 +369,35 @@ void cpu_idle(void) */ void default_idle(void) { - if (hlt_use_halt()) { - trace_power_start_rcuidle(POWER_CSTATE, 1, smp_processor_id()); - trace_cpu_idle_rcuidle(1, smp_processor_id()); - current_thread_info()->status &= ~TS_POLLING; - /* - * TS_POLLING-cleared state must be visible before we - * test NEED_RESCHED: - */ - smp_mb(); + trace_cpu_idle_rcuidle(1, smp_processor_id()); + current_thread_info()->status &= ~TS_POLLING; + /* + * TS_POLLING-cleared state must be visible before we + * test NEED_RESCHED: + */ + smp_mb(); - if (!need_resched()) - safe_halt(); /* enables interrupts racelessly */ - else - local_irq_enable(); - current_thread_info()->status |= TS_POLLING; - trace_power_end_rcuidle(smp_processor_id()); - trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id()); - } else { + if (!need_resched()) + safe_halt(); /* enables interrupts racelessly */ + else local_irq_enable(); - /* loop is done by the caller */ - cpu_relax(); - } + current_thread_info()->status |= TS_POLLING; + trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id()); } #ifdef CONFIG_APM_MODULE EXPORT_SYMBOL(default_idle); #endif -bool set_pm_idle_to_default(void) +#ifdef CONFIG_XEN +bool xen_set_default_idle(void) { - bool ret = !!pm_idle; + bool ret = !!x86_idle; - pm_idle = default_idle; + x86_idle = default_idle; return ret; } +#endif void stop_this_cpu(void *dummy) { local_irq_disable(); @@ -454,31 +407,8 @@ void stop_this_cpu(void *dummy) set_cpu_online(smp_processor_id(), false); disable_local_APIC(); - for (;;) { - if (hlt_works(smp_processor_id())) - 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 *)¤t_thread_info()->flags); - - __monitor((void *)¤t_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(); + for (;;) + halt(); } /* @@ -488,62 +418,13 @@ static void mwait_idle(void) */ static void poll_idle(void) { - trace_power_start_rcuidle(POWER_CSTATE, 0, smp_processor_id()); trace_cpu_idle_rcuidle(0, smp_processor_id()); local_irq_enable(); while (!need_resched()) cpu_relax(); - trace_power_end_rcuidle(smp_processor_id()); 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); @@ -608,31 +489,24 @@ static void amd_e400_idle(void) void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c) { #ifdef CONFIG_SMP - if (pm_idle == poll_idle && smp_num_siblings > 1) { + if (x86_idle == poll_idle && smp_num_siblings > 1) pr_warn_once("WARNING: polling idle and HT enabled, performance may degrade\n"); - } #endif - if (pm_idle) + 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"); - pm_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"); - pm_idle = amd_e400_idle; + x86_idle = amd_e400_idle; } else - pm_idle = default_idle; + x86_idle = default_idle; } void __init init_amd_e400_c1e_mask(void) { /* If we're using amd_e400_idle, we need to allocate amd_e400_c1e_mask. */ - if (pm_idle == amd_e400_idle) + if (x86_idle == amd_e400_idle) zalloc_cpumask_var(&amd_e400_c1e_mask, GFP_KERNEL); } @@ -643,11 +517,8 @@ static int __init idle_setup(char *str) if (!strcmp(str, "poll")) { pr_info("using polling idle threads\n"); - pm_idle = poll_idle; + 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 @@ -656,7 +527,7 @@ static int __init idle_setup(char *str) * To continue to load the CPU idle driver, don't touch * the boot_option_idle_override. */ - pm_idle = default_idle; + x86_idle = default_idle; boot_option_idle_override = IDLE_HALT; } else if (!strcmp(str, "nomwait")) { /* |