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authorRichard Weinberger <richard@nod.at>2012-03-25 21:00:04 (GMT)
committerIngo Molnar <mingo@kernel.org>2012-03-26 01:16:07 (GMT)
commit90e240142bd31ff10aeda5a280a53153f4eff004 (patch)
treeae612bacc2cfd2fedc4c5c22c29dd326f8b93ae7 /arch/x86/kernel/process_64.c
parentf5243d6de7ae232e1d81e44ae9756bbd8c988fcd (diff)
x86: Merge the x86_32 and x86_64 cpu_idle() functions
Both functions are mostly identical. The differences are: - x86_32's cpu_idle() makes use of check_pgt_cache(), which is a nop on both x86_32 and x86_64. - x86_64's cpu_idle() uses enter/__exit_idle/(), on x86_32 these function are a nop. - In contrast to x86_32, x86_64 calls rcu_idle_enter/exit() in the innermost loop because idle notifications need RCU. Calling these function on x86_32 also in the innermost loop does not hurt. So we can merge both functions. Signed-off-by: Richard Weinberger <richard@nod.at> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: paulmck@linux.vnet.ibm.com Cc: josh@joshtriplett.org Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1332709204-22496-1-git-send-email-richard@nod.at Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/process_64.c')
-rw-r--r--arch/x86/kernel/process_64.c107
1 files changed, 0 insertions, 107 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 292da13..ce5e34f 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -14,7 +14,6 @@
* This file handles the architecture-dependent parts of process handling..
*/
-#include <linux/stackprotector.h>
#include <linux/cpu.h>
#include <linux/errno.h>
#include <linux/sched.h>
@@ -32,12 +31,10 @@
#include <linux/notifier.h>
#include <linux/kprobes.h>
#include <linux/kdebug.h>
-#include <linux/tick.h>
#include <linux/prctl.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/ftrace.h>
-#include <linux/cpuidle.h>
#include <asm/pgtable.h>
#include <asm/system.h>
@@ -52,114 +49,10 @@
#include <asm/idle.h>
#include <asm/syscalls.h>
#include <asm/debugreg.h>
-#include <asm/nmi.h>
asmlinkage extern void ret_from_fork(void);
DEFINE_PER_CPU(unsigned long, old_rsp);
-static DEFINE_PER_CPU(unsigned char, is_idle);
-
-static ATOMIC_NOTIFIER_HEAD(idle_notifier);
-
-void idle_notifier_register(struct notifier_block *n)
-{
- atomic_notifier_chain_register(&idle_notifier, n);
-}
-EXPORT_SYMBOL_GPL(idle_notifier_register);
-
-void idle_notifier_unregister(struct notifier_block *n)
-{
- atomic_notifier_chain_unregister(&idle_notifier, n);
-}
-EXPORT_SYMBOL_GPL(idle_notifier_unregister);
-
-void enter_idle(void)
-{
- percpu_write(is_idle, 1);
- atomic_notifier_call_chain(&idle_notifier, IDLE_START, NULL);
-}
-
-static void __exit_idle(void)
-{
- if (x86_test_and_clear_bit_percpu(0, is_idle) == 0)
- return;
- atomic_notifier_call_chain(&idle_notifier, IDLE_END, NULL);
-}
-
-/* Called from interrupts to signify idle end */
-void exit_idle(void)
-{
- /* idle loop has pid 0 */
- if (current->pid)
- return;
- __exit_idle();
-}
-
-#ifndef CONFIG_SMP
-static inline void play_dead(void)
-{
- BUG();
-}
-#endif
-
-/*
- * The idle thread. There's no useful work to be
- * done, so just try to conserve power and have a
- * low exit latency (ie sit in a loop waiting for
- * somebody to say that they'd like to reschedule)
- */
-void cpu_idle(void)
-{
- current_thread_info()->status |= TS_POLLING;
-
- /*
- * If we're the non-boot CPU, nothing set the stack canary up
- * for us. CPU0 already has it initialized but no harm in
- * doing it again. This is a good place for updating it, as
- * we wont ever return from this function (so the invalid
- * canaries already on the stack wont ever trigger).
- */
- boot_init_stack_canary();
-
- /* endless idle loop with no priority at all */
- while (1) {
- tick_nohz_idle_enter();
- while (!need_resched()) {
-
- rmb();
-
- if (cpu_is_offline(smp_processor_id()))
- play_dead();
- /*
- * Idle routines should keep interrupts disabled
- * from here on, until they go to idle.
- * Otherwise, idle callbacks can misfire.
- */
- local_touch_nmi();
- local_irq_disable();
- enter_idle();
- /* Don't trace irqs off for idle */
- stop_critical_timings();
-
- /* enter_idle() needs rcu for notifiers */
- rcu_idle_enter();
-
- if (cpuidle_idle_call())
- pm_idle();
-
- rcu_idle_exit();
- start_critical_timings();
-
- /* In many cases the interrupt that ended idle
- has already called exit_idle. But some idle
- loops can be woken up without interrupt. */
- __exit_idle();
- }
-
- tick_nohz_idle_exit();
- schedule_preempt_disabled();
- }
-}
/* Prints also some state that isn't saved in the pt_regs */
void __show_regs(struct pt_regs *regs, int all)

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