From ee761f629d598579594d7e1eb8c552f3c5f71e4d Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 21 Mar 2013 22:49:32 +0100 Subject: arch: Consolidate tsk_is_polling() Move it to a common place. Preparatory patch for implementing set/clear for the idle need_resched poll implementation. Signed-off-by: Thomas Gleixner Cc: Linus Torvalds Cc: Rusty Russell Cc: Paul McKenney Cc: Peter Zijlstra Reviewed-by: Cc: Srivatsa S. Bhat Cc: Magnus Damm Link: http://lkml.kernel.org/r/20130321215233.446034505@linutronix.de Signed-off-by: Thomas Gleixner --- arch/ia64/include/asm/thread_info.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'arch/ia64') diff --git a/arch/ia64/include/asm/thread_info.h b/arch/ia64/include/asm/thread_info.h index 020d655ed082..cade13dd0299 100644 --- a/arch/ia64/include/asm/thread_info.h +++ b/arch/ia64/include/asm/thread_info.h @@ -131,8 +131,6 @@ struct thread_info { #define TS_POLLING 1 /* true if in idle loop and not sleeping */ #define TS_RESTORE_SIGMASK 2 /* restore signal mask in do_signal() */ -#define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING) - #ifndef __ASSEMBLY__ #define HAVE_SET_RESTORE_SIGMASK 1 static inline void set_restore_sigmask(void) -- cgit v1.2.1 From 91d591c387af34db00c39da2d1d25e69a91cf591 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 21 Mar 2013 22:49:47 +0100 Subject: ia64: Use generic idle loop Signed-off-by: Thomas Gleixner Cc: Linus Torvalds Cc: Rusty Russell Cc: Paul McKenney Cc: Peter Zijlstra Reviewed-by: Cc: Srivatsa S. Bhat Cc: Magnus Damm Cc: Tony Luck Link: http://lkml.kernel.org/r/20130321215234.406851909@linutronix.de Signed-off-by: Thomas Gleixner --- arch/ia64/Kconfig | 1 + arch/ia64/kernel/perfmon.c | 14 +++------ arch/ia64/kernel/process.c | 78 ++++++++++------------------------------------ arch/ia64/kernel/smpboot.c | 2 +- 4 files changed, 23 insertions(+), 72 deletions(-) (limited to 'arch/ia64') diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig index 9a02f71c6b1f..e0b39c3cb789 100644 --- a/arch/ia64/Kconfig +++ b/arch/ia64/Kconfig @@ -35,6 +35,7 @@ config IA64 select ARCH_HAVE_NMI_SAFE_CMPXCHG select GENERIC_IOMAP select GENERIC_SMP_IDLE_THREAD + select GENERIC_IDLE_LOOP select ARCH_INIT_TASK select ARCH_TASK_STRUCT_ALLOCATOR select ARCH_THREAD_INFO_ALLOCATOR diff --git a/arch/ia64/kernel/perfmon.c b/arch/ia64/kernel/perfmon.c index 2eda28414abb..9ea25fce06d5 100644 --- a/arch/ia64/kernel/perfmon.c +++ b/arch/ia64/kernel/perfmon.c @@ -42,6 +42,7 @@ #include #include #include +#include #include #include @@ -1322,8 +1323,6 @@ out: } EXPORT_SYMBOL(pfm_unregister_buffer_fmt); -extern void update_pal_halt_status(int); - static int pfm_reserve_session(struct task_struct *task, int is_syswide, unsigned int cpu) { @@ -1371,9 +1370,9 @@ pfm_reserve_session(struct task_struct *task, int is_syswide, unsigned int cpu) cpu)); /* - * disable default_idle() to go to PAL_HALT + * Force idle() into poll mode */ - update_pal_halt_status(0); + cpu_idle_poll_ctrl(true); UNLOCK_PFS(flags); @@ -1430,11 +1429,8 @@ pfm_unreserve_session(pfm_context_t *ctx, int is_syswide, unsigned int cpu) is_syswide, cpu)); - /* - * if possible, enable default_idle() to go into PAL_HALT - */ - if (pfm_sessions.pfs_task_sessions == 0 && pfm_sessions.pfs_sys_sessions == 0) - update_pal_halt_status(1); + /* Undo forced polling. Last session reenables pal_halt */ + cpu_idle_poll_ctrl(false); UNLOCK_PFS(flags); diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c index 6f7dc8b7b35c..a26fc640e4ce 100644 --- a/arch/ia64/kernel/process.c +++ b/arch/ia64/kernel/process.c @@ -209,41 +209,13 @@ do_notify_resume_user(sigset_t *unused, struct sigscratch *scr, long in_syscall) local_irq_disable(); /* force interrupt disable */ } -static int pal_halt = 1; -static int can_do_pal_halt = 1; - static int __init nohalt_setup(char * str) { - pal_halt = can_do_pal_halt = 0; + cpu_idle_poll_ctrl(true); return 1; } __setup("nohalt", nohalt_setup); -void -update_pal_halt_status(int status) -{ - can_do_pal_halt = pal_halt && status; -} - -/* - * We use this if we don't have any better idle routine.. - */ -void -default_idle (void) -{ - local_irq_enable(); - while (!need_resched()) { - if (can_do_pal_halt) { - local_irq_disable(); - if (!need_resched()) { - safe_halt(); - } - local_irq_enable(); - } else - cpu_relax(); - } -} - #ifdef CONFIG_HOTPLUG_CPU /* We don't actually take CPU down, just spin without interrupts. */ static inline void play_dead(void) @@ -270,47 +242,29 @@ static inline void play_dead(void) } #endif /* CONFIG_HOTPLUG_CPU */ -void __attribute__((noreturn)) -cpu_idle (void) +void arch_cpu_idle_dead(void) +{ + play_dead(); +} + +void arch_cpu_idle(void) { void (*mark_idle)(int) = ia64_mark_idle; - int cpu = smp_processor_id(); - - /* endless idle loop with no priority at all */ - while (1) { - rcu_idle_enter(); - if (can_do_pal_halt) { - current_thread_info()->status &= ~TS_POLLING; - /* - * TS_POLLING-cleared state must be visible before we - * test NEED_RESCHED: - */ - smp_mb(); - } else { - current_thread_info()->status |= TS_POLLING; - } - if (!need_resched()) { #ifdef CONFIG_SMP - min_xtp(); + min_xtp(); #endif - rmb(); - if (mark_idle) - (*mark_idle)(1); + rmb(); + if (mark_idle) + (*mark_idle)(1); + + safe_halt(); - default_idle(); - if (mark_idle) - (*mark_idle)(0); + if (mark_idle) + (*mark_idle)(0); #ifdef CONFIG_SMP - normal_xtp(); + normal_xtp(); #endif - } - rcu_idle_exit(); - schedule_preempt_disabled(); - check_pgt_cache(); - if (cpu_is_offline(cpu)) - play_dead(); - } } void diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c index 500f1e4d9f9d..8d87168d218d 100644 --- a/arch/ia64/kernel/smpboot.c +++ b/arch/ia64/kernel/smpboot.c @@ -455,7 +455,7 @@ start_secondary (void *unused) preempt_disable(); smp_callin(); - cpu_idle(); + cpu_startup_entry(CPUHP_ONLINE); return 0; } -- cgit v1.2.1 From 2412aa1293a4159c610616305c17efd237c8208d Mon Sep 17 00:00:00 2001 From: "Luck, Tony" Date: Tue, 16 Apr 2013 11:35:56 -0700 Subject: ia64: Make sure interrupts enabled when we "safe_halt()" In commit d166991234347215dc23fc9dc15a63a83a1a54e1 idle: Implement generic idle function Thomas Gleixner cleaned up many things but perturbed some fragile code that was keeping ia64 alive. So we started seeing: WARNING: at kernel/cpu/idle.c:94 cpu_idle_loop+0x360/0x380() and other unpleasantness like system hangs during boot. We really shouldn't ever halt with interrupts disabled. Signed-off-by: Tony Luck Cc: Linus Torvalds Cc: Rusty Russell Cc: Peter Zijlstra Cc: Srivatsa S. Bhat Cc: Paul McKenney Cc: magnus.damm@gmail.com Link: http://lkml.kernel.org/r/516d9a0c26048eae9c@agluck-desk.sc.intel.com Signed-off-by: Thomas Gleixner --- arch/ia64/include/asm/irqflags.h | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/ia64') diff --git a/arch/ia64/include/asm/irqflags.h b/arch/ia64/include/asm/irqflags.h index 2b68d856dc78..1bf2cf2f4ab4 100644 --- a/arch/ia64/include/asm/irqflags.h +++ b/arch/ia64/include/asm/irqflags.h @@ -89,6 +89,7 @@ static inline bool arch_irqs_disabled(void) static inline void arch_safe_halt(void) { + arch_local_irq_enable(); ia64_pal_halt_light(); /* PAL_HALT_LIGHT */ } -- cgit v1.2.1 From d190e8195b90bc1e65c494fe08e54e9e581bfd16 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 17 Apr 2013 10:33:13 +0200 Subject: idle: Remove GENERIC_IDLE_LOOP config switch All archs are converted over. Remove the config switch and the fallback code. Signed-off-by: Thomas Gleixner --- arch/ia64/Kconfig | 1 - 1 file changed, 1 deletion(-) (limited to 'arch/ia64') diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig index e0b39c3cb789..9a02f71c6b1f 100644 --- a/arch/ia64/Kconfig +++ b/arch/ia64/Kconfig @@ -35,7 +35,6 @@ config IA64 select ARCH_HAVE_NMI_SAFE_CMPXCHG select GENERIC_IOMAP select GENERIC_SMP_IDLE_THREAD - select GENERIC_IDLE_LOOP select ARCH_INIT_TASK select ARCH_TASK_STRUCT_ALLOCATOR select ARCH_THREAD_INFO_ALLOCATOR -- cgit v1.2.1