diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-04-30 07:50:17 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-04-30 07:50:17 -0700 |
commit | 8700c95adb033843fc163d112b9d21d4fda78018 (patch) | |
tree | 7bb9a37b8fe6328f63a61d88063c556346001098 /kernel | |
parent | 16fa94b532b1958f508e07eca1a9256351241fbc (diff) | |
parent | d190e8195b90bc1e65c494fe08e54e9e581bfd16 (diff) |
Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull SMP/hotplug changes from Ingo Molnar:
"This is a pretty large, multi-arch series unifying and generalizing
the various disjunct pieces of idle routines that architectures have
historically copied from each other and have grown in random, wildly
inconsistent and sometimes buggy directions:
101 files changed, 455 insertions(+), 1328 deletions(-)
this went through a number of review and test iterations before it was
committed, it was tested on various architectures, was exposed to
linux-next for quite some time - nevertheless it might cause problems
on architectures that don't read the mailing lists and don't regularly
test linux-next.
This cat herding excercise was motivated by the -rt kernel, and was
brought to you by Thomas "the Whip" Gleixner."
* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
idle: Remove GENERIC_IDLE_LOOP config switch
um: Use generic idle loop
ia64: Make sure interrupts enabled when we "safe_halt()"
sparc: Use generic idle loop
idle: Remove unused ARCH_HAS_DEFAULT_IDLE
bfin: Fix typo in arch_cpu_idle()
xtensa: Use generic idle loop
x86: Use generic idle loop
unicore: Use generic idle loop
tile: Use generic idle loop
tile: Enter idle with preemption disabled
sh: Use generic idle loop
score: Use generic idle loop
s390: Use generic idle loop
powerpc: Use generic idle loop
parisc: Use generic idle loop
openrisc: Use generic idle loop
mn10300: Use generic idle loop
mips: Use generic idle loop
microblaze: Use generic idle loop
...
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/Makefile | 1 | ||||
-rw-r--r-- | kernel/cpu/Makefile | 1 | ||||
-rw-r--r-- | kernel/cpu/idle.c | 107 | ||||
-rw-r--r-- | kernel/sched/core.c | 5 |
4 files changed, 109 insertions, 5 deletions
diff --git a/kernel/Makefile b/kernel/Makefile index bbde5f1a4486..d1574d47cf27 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -24,6 +24,7 @@ endif obj-y += sched/ obj-y += power/ +obj-y += cpu/ obj-$(CONFIG_CHECKPOINT_RESTORE) += kcmp.o obj-$(CONFIG_FREEZER) += freezer.o diff --git a/kernel/cpu/Makefile b/kernel/cpu/Makefile new file mode 100644 index 000000000000..59ab052ef7a0 --- /dev/null +++ b/kernel/cpu/Makefile @@ -0,0 +1 @@ +obj-y = idle.o diff --git a/kernel/cpu/idle.c b/kernel/cpu/idle.c new file mode 100644 index 000000000000..168cf407a254 --- /dev/null +++ b/kernel/cpu/idle.c @@ -0,0 +1,107 @@ +/* + * Generic entry point for the idle threads + */ +#include <linux/sched.h> +#include <linux/cpu.h> +#include <linux/tick.h> +#include <linux/mm.h> + +#include <asm/tlb.h> + +#include <trace/events/power.h> + +static int __read_mostly cpu_idle_force_poll; + +void cpu_idle_poll_ctrl(bool enable) +{ + if (enable) { + cpu_idle_force_poll++; + } else { + cpu_idle_force_poll--; + WARN_ON_ONCE(cpu_idle_force_poll < 0); + } +} + +#ifdef CONFIG_GENERIC_IDLE_POLL_SETUP +static int __init cpu_idle_poll_setup(char *__unused) +{ + cpu_idle_force_poll = 1; + return 1; +} +__setup("nohlt", cpu_idle_poll_setup); + +static int __init cpu_idle_nopoll_setup(char *__unused) +{ + cpu_idle_force_poll = 0; + return 1; +} +__setup("hlt", cpu_idle_nopoll_setup); +#endif + +static inline int cpu_idle_poll(void) +{ + trace_cpu_idle_rcuidle(0, smp_processor_id()); + local_irq_enable(); + while (!need_resched()) + cpu_relax(); + trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id()); + return 1; +} + +/* Weak implementations for optional arch specific functions */ +void __weak arch_cpu_idle_prepare(void) { } +void __weak arch_cpu_idle_enter(void) { } +void __weak arch_cpu_idle_exit(void) { } +void __weak arch_cpu_idle_dead(void) { } +void __weak arch_cpu_idle(void) +{ + cpu_idle_force_poll = 1; +} + +/* + * Generic idle loop implementation + */ +static void cpu_idle_loop(void) +{ + while (1) { + tick_nohz_idle_enter(); + + while (!need_resched()) { + check_pgt_cache(); + rmb(); + + if (cpu_is_offline(smp_processor_id())) + arch_cpu_idle_dead(); + + local_irq_disable(); + arch_cpu_idle_enter(); + + if (cpu_idle_force_poll) { + cpu_idle_poll(); + } else { + current_clr_polling(); + if (!need_resched()) { + stop_critical_timings(); + rcu_idle_enter(); + arch_cpu_idle(); + WARN_ON_ONCE(irqs_disabled()); + rcu_idle_exit(); + start_critical_timings(); + } else { + local_irq_enable(); + } + current_set_polling(); + } + arch_cpu_idle_exit(); + } + tick_nohz_idle_exit(); + schedule_preempt_disabled(); + } +} + +void cpu_startup_entry(enum cpuhp_state state) +{ + current_set_polling(); + arch_cpu_idle_prepare(); + cpu_idle_loop(); +} diff --git a/kernel/sched/core.c b/kernel/sched/core.c index ebdb19541218..c70a8814a767 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -512,11 +512,6 @@ static inline void init_hrtick(void) * the target CPU. */ #ifdef CONFIG_SMP - -#ifndef tsk_is_polling -#define tsk_is_polling(t) 0 -#endif - void resched_task(struct task_struct *p) { int cpu; |