1268fbc746
Those two APIs were provided to optimize the calls of tick_nohz_idle_enter() and rcu_idle_enter() into a single irq disabled section. This way no interrupt happening in-between would needlessly process any RCU job. Now we are talking about an optimization for which benefits have yet to be measured. Let's start simple and completely decouple idle rcu and dyntick idle logics to simplify. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
80 lines
1.9 KiB
C
80 lines
1.9 KiB
C
/*
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* OpenRISC idle.c
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*
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* Linux architectural port borrowing liberally from similar works of
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* others. All original copyrights apply as per the original source
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* declaration.
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*
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* Modifications for the OpenRISC architecture:
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* Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
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* Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Idle daemon for or32. Idle daemon will handle any action
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* that needs to be taken when the system becomes idle.
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*/
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#include <linux/errno.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/smp.h>
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#include <linux/stddef.h>
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#include <linux/unistd.h>
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#include <linux/ptrace.h>
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#include <linux/slab.h>
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#include <linux/tick.h>
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#include <asm/pgtable.h>
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#include <asm/uaccess.h>
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#include <asm/system.h>
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#include <asm/io.h>
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#include <asm/processor.h>
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#include <asm/mmu.h>
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#include <asm/cache.h>
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#include <asm/pgalloc.h>
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void (*powersave) (void) = NULL;
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static inline void pm_idle(void)
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{
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barrier();
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}
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void cpu_idle(void)
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{
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set_thread_flag(TIF_POLLING_NRFLAG);
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/* endless idle loop with no priority at all */
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while (1) {
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tick_nohz_idle_enter();
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rcu_idle_enter();
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while (!need_resched()) {
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check_pgt_cache();
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rmb();
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clear_thread_flag(TIF_POLLING_NRFLAG);
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local_irq_disable();
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/* Don't trace irqs off for idle */
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stop_critical_timings();
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if (!need_resched() && powersave != NULL)
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powersave();
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start_critical_timings();
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local_irq_enable();
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set_thread_flag(TIF_POLLING_NRFLAG);
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}
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rcu_idle_exit();
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tick_nohz_idle_exit();
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preempt_enable_no_resched();
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schedule();
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preempt_disable();
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}
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}
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