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kernel/softirq.c
18.8 KB
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/* * linux/kernel/softirq.c * * Copyright (C) 1992 Linus Torvalds * |
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* Distribute under GPLv2. * * Rewritten. Old one was good in 2.2, but in 2.3 it was immoral. --ANK (990903) |
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*/ |
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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#include <linux/export.h> |
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#include <linux/kernel_stat.h> #include <linux/interrupt.h> #include <linux/init.h> #include <linux/mm.h> #include <linux/notifier.h> #include <linux/percpu.h> #include <linux/cpu.h> |
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#include <linux/freezer.h> |
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#include <linux/kthread.h> #include <linux/rcupdate.h> |
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#include <linux/ftrace.h> |
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#include <linux/smp.h> |
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#include <linux/smpboot.h> |
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#include <linux/tick.h> |
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#include <linux/irq.h> |
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#define CREATE_TRACE_POINTS |
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#include <trace/events/irq.h> |
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|
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/* - No shared variables, all the data are CPU local. - If a softirq needs serialization, let it serialize itself by its own spinlocks. - Even if softirq is serialized, only local cpu is marked for execution. Hence, we get something sort of weak cpu binding. Though it is still not clear, will it result in better locality or will not. Examples: - NET RX softirq. It is multithreaded and does not require any global serialization. - NET TX softirq. It kicks software netdevice queues, hence it is logically serialized per device, but this serialization is invisible to common code. - Tasklets: serialized wrt itself. */ #ifndef __ARCH_IRQ_STAT irq_cpustat_t irq_stat[NR_CPUS] ____cacheline_aligned; EXPORT_SYMBOL(irq_stat); #endif |
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static struct softirq_action softirq_vec[NR_SOFTIRQS] __cacheline_aligned_in_smp; |
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|
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DEFINE_PER_CPU(struct task_struct *, ksoftirqd); |
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|
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const char * const softirq_to_name[NR_SOFTIRQS] = { |
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"HI", "TIMER", "NET_TX", "NET_RX", "BLOCK", "BLOCK_IOPOLL", |
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"TASKLET", "SCHED", "HRTIMER", "RCU" |
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}; |
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/* * we cannot loop indefinitely here to avoid userspace starvation, * but we also don't want to introduce a worst case 1/HZ latency * to the pending events, so lets the scheduler to balance * the softirq load for us. */ |
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static void wakeup_softirqd(void) |
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{ /* Interrupts are disabled: no need to stop preemption */ |
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struct task_struct *tsk = __this_cpu_read(ksoftirqd); |
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if (tsk && tsk->state != TASK_RUNNING) wake_up_process(tsk); } /* |
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* preempt_count and SOFTIRQ_OFFSET usage: * - preempt_count is changed by SOFTIRQ_OFFSET on entering or leaving * softirq processing. * - preempt_count is changed by SOFTIRQ_DISABLE_OFFSET (= 2 * SOFTIRQ_OFFSET) * on local_bh_disable or local_bh_enable. * This lets us distinguish between whether we are currently processing * softirq and whether we just have bh disabled. */ /* |
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* This one is for softirq.c-internal use, * where hardirqs are disabled legitimately: */ |
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#ifdef CONFIG_TRACE_IRQFLAGS |
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void __local_bh_disable_ip(unsigned long ip, unsigned int cnt) |
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{ unsigned long flags; WARN_ON_ONCE(in_irq()); raw_local_irq_save(flags); |
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/* |
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* The preempt tracer hooks into preempt_count_add and will break |
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* lockdep because it calls back into lockdep after SOFTIRQ_OFFSET * is set and before current->softirq_enabled is cleared. * We must manually increment preempt_count here and manually * call the trace_preempt_off later. */ |
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__preempt_count_add(cnt); |
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/* * Were softirqs turned off above: */ |
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if (softirq_count() == (cnt & SOFTIRQ_MASK)) |
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trace_softirqs_off(ip); raw_local_irq_restore(flags); |
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|
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if (preempt_count() == cnt) |
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trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); |
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} |
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EXPORT_SYMBOL(__local_bh_disable_ip); |
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#endif /* CONFIG_TRACE_IRQFLAGS */ |
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|
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static void __local_bh_enable(unsigned int cnt) { |
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WARN_ON_ONCE(!irqs_disabled()); |
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if (softirq_count() == (cnt & SOFTIRQ_MASK)) |
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trace_softirqs_on(_RET_IP_); |
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preempt_count_sub(cnt); |
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} |
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/* * Special-case - softirqs can safely be enabled in * cond_resched_softirq(), or by __do_softirq(), * without processing still-pending softirqs: */ void _local_bh_enable(void) { |
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WARN_ON_ONCE(in_irq()); |
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__local_bh_enable(SOFTIRQ_DISABLE_OFFSET); |
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} |
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EXPORT_SYMBOL(_local_bh_enable); |
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void __local_bh_enable_ip(unsigned long ip, unsigned int cnt) |
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{ |
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WARN_ON_ONCE(in_irq() || irqs_disabled()); |
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#ifdef CONFIG_TRACE_IRQFLAGS |
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local_irq_disable(); |
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#endif |
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/* * Are softirqs going to be turned on now: */ |
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if (softirq_count() == SOFTIRQ_DISABLE_OFFSET) |
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trace_softirqs_on(ip); |
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/* * Keep preemption disabled until we are done with * softirq processing: |
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*/ |
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preempt_count_sub(cnt - 1); |
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|
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if (unlikely(!in_interrupt() && local_softirq_pending())) { /* * Run softirq if any pending. And do it in its own stack * as we may be calling this deep in a task call stack already. */ |
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do_softirq(); |
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} |
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|
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preempt_count_dec(); |
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#ifdef CONFIG_TRACE_IRQFLAGS |
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local_irq_enable(); |
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#endif |
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preempt_check_resched(); } |
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EXPORT_SYMBOL(__local_bh_enable_ip); |
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/* |
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* We restart softirq processing for at most MAX_SOFTIRQ_RESTART times, * but break the loop if need_resched() is set or after 2 ms. * The MAX_SOFTIRQ_TIME provides a nice upper bound in most cases, but in * certain cases, such as stop_machine(), jiffies may cease to * increment and so we need the MAX_SOFTIRQ_RESTART limit as * well to make sure we eventually return from this method. |
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* |
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* These limits have been established via experimentation. |
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* The two things to balance is latency against fairness - * we want to handle softirqs as soon as possible, but they * should not be able to lock up the box. */ |
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#define MAX_SOFTIRQ_TIME msecs_to_jiffies(2) |
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#define MAX_SOFTIRQ_RESTART 10 |
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|
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#ifdef CONFIG_TRACE_IRQFLAGS /* |
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* When we run softirqs from irq_exit() and thus on the hardirq stack we need * to keep the lockdep irq context tracking as tight as possible in order to * not miss-qualify lock contexts and miss possible deadlocks. */ |
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static inline bool lockdep_softirq_start(void) |
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{ |
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bool in_hardirq = false; |
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|
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if (trace_hardirq_context(current)) { in_hardirq = true; |
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trace_hardirq_exit(); |
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} |
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lockdep_softirq_enter(); |
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return in_hardirq; |
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} |
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static inline void lockdep_softirq_end(bool in_hardirq) |
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{ lockdep_softirq_exit(); |
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if (in_hardirq) |
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trace_hardirq_enter(); |
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} |
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#else |
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static inline bool lockdep_softirq_start(void) { return false; } static inline void lockdep_softirq_end(bool in_hardirq) { } |
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#endif |
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asmlinkage void __do_softirq(void) { |
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unsigned long end = jiffies + MAX_SOFTIRQ_TIME; |
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unsigned long old_flags = current->flags; |
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int max_restart = MAX_SOFTIRQ_RESTART; |
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struct softirq_action *h; |
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bool in_hardirq; |
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__u32 pending; |
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int softirq_bit; |
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int cpu; |
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/* * Mask out PF_MEMALLOC s current task context is borrowed for the * softirq. A softirq handled such as network RX might set PF_MEMALLOC * again if the socket is related to swap */ current->flags &= ~PF_MEMALLOC; |
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pending = local_softirq_pending(); |
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account_irq_enter_time(current); |
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|
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__local_bh_disable_ip(_RET_IP_, SOFTIRQ_OFFSET); |
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in_hardirq = lockdep_softirq_start(); |
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|
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cpu = smp_processor_id(); restart: /* Reset the pending bitmask before enabling irqs */ |
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set_softirq_pending(0); |
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|
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local_irq_enable(); |
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h = softirq_vec; |
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while ((softirq_bit = ffs(pending))) { unsigned int vec_nr; int prev_count; h += softirq_bit - 1; vec_nr = h - softirq_vec; prev_count = preempt_count(); kstat_incr_softirqs_this_cpu(vec_nr); trace_softirq_entry(vec_nr); h->action(h); trace_softirq_exit(vec_nr); if (unlikely(prev_count != preempt_count())) { |
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pr_err("huh, entered softirq %u %s %p with preempt_count %08x, exited with %08x? ", |
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vec_nr, softirq_to_name[vec_nr], h->action, prev_count, preempt_count()); preempt_count_set(prev_count); |
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} |
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rcu_bh_qs(cpu); |
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h++; |
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pending >>= softirq_bit; } |
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|
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local_irq_disable(); |
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pending = local_softirq_pending(); |
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if (pending) { |
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if (time_before(jiffies, end) && !need_resched() && --max_restart) |
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goto restart; |
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|
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wakeup_softirqd(); |
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} |
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|
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lockdep_softirq_end(in_hardirq); |
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account_irq_exit_time(current); |
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__local_bh_enable(SOFTIRQ_OFFSET); |
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WARN_ON_ONCE(in_interrupt()); |
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tsk_restore_flags(current, old_flags, PF_MEMALLOC); |
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} |
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asmlinkage void do_softirq(void) { __u32 pending; unsigned long flags; if (in_interrupt()) return; local_irq_save(flags); pending = local_softirq_pending(); if (pending) |
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do_softirq_own_stack(); |
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local_irq_restore(flags); } |
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/* * Enter an interrupt context. */ void irq_enter(void) { |
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rcu_irq_enter(); |
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if (is_idle_task(current) && !in_interrupt()) { |
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/* * Prevent raise_softirq from needlessly waking up ksoftirqd * here, as softirq will be serviced on return from interrupt. */ local_bh_disable(); |
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tick_irq_enter(); |
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_local_bh_enable(); } __irq_enter(); |
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} |
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static inline void invoke_softirq(void) { |
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if (!force_irqthreads) { |
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#ifdef CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK |
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/* * We can safely execute softirq on the current stack if * it is the irq stack, because it should be near empty |
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* at this stage. */ __do_softirq(); #else /* * Otherwise, irq_exit() is called on the task stack that can * be potentially deep already. So call softirq in its own stack * to prevent from any overrun. |
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*/ |
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do_softirq_own_stack(); |
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#endif |
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} else { |
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wakeup_softirqd(); |
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} |
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} |
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|
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static inline void tick_irq_exit(void) { #ifdef CONFIG_NO_HZ_COMMON int cpu = smp_processor_id(); /* Make sure that timer wheel updates are propagated */ if ((idle_cpu(cpu) && !need_resched()) || tick_nohz_full_cpu(cpu)) { if (!in_interrupt()) tick_nohz_irq_exit(); } #endif } |
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/* * Exit an interrupt context. Process softirqs if needed and possible: */ void irq_exit(void) { |
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#ifndef __ARCH_IRQ_EXIT_IRQS_DISABLED |
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local_irq_disable(); |
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#else WARN_ON_ONCE(!irqs_disabled()); #endif |
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account_irq_exit_time(current); |
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preempt_count_sub(HARDIRQ_OFFSET); |
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if (!in_interrupt() && local_softirq_pending()) invoke_softirq(); |
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|
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tick_irq_exit(); |
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rcu_irq_exit(); |
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trace_hardirq_exit(); /* must be last! */ |
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} /* * This function must run with irqs disabled! */ |
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inline void raise_softirq_irqoff(unsigned int nr) |
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{ __raise_softirq_irqoff(nr); /* * If we're in an interrupt or softirq, we're done * (this also catches softirq-disabled code). We will * actually run the softirq once we return from * the irq or softirq. * * Otherwise we wake up ksoftirqd to make sure we * schedule the softirq soon. */ if (!in_interrupt()) wakeup_softirqd(); } |
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void raise_softirq(unsigned int nr) |
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{ unsigned long flags; local_irq_save(flags); raise_softirq_irqoff(nr); local_irq_restore(flags); } |
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void __raise_softirq_irqoff(unsigned int nr) { trace_softirq_raise(nr); or_softirq_pending(1UL << nr); } |
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void open_softirq(int nr, void (*action)(struct softirq_action *)) |
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{ |
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softirq_vec[nr].action = action; } |
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/* * Tasklets */ |
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struct tasklet_head { |
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struct tasklet_struct *head; struct tasklet_struct **tail; |
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}; |
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424 425 |
static DEFINE_PER_CPU(struct tasklet_head, tasklet_vec); static DEFINE_PER_CPU(struct tasklet_head, tasklet_hi_vec); |
1da177e4c Linux-2.6.12-rc2 |
426 |
|
7ad5b3a50 kernel: remove fa... |
427 |
void __tasklet_schedule(struct tasklet_struct *t) |
1da177e4c Linux-2.6.12-rc2 |
428 429 430 431 |
{ unsigned long flags; local_irq_save(flags); |
48f20a9a9 tasklets: execute... |
432 |
t->next = NULL; |
909ea9646 core: Replace __g... |
433 434 |
*__this_cpu_read(tasklet_vec.tail) = t; __this_cpu_write(tasklet_vec.tail, &(t->next)); |
1da177e4c Linux-2.6.12-rc2 |
435 436 437 |
raise_softirq_irqoff(TASKLET_SOFTIRQ); local_irq_restore(flags); } |
1da177e4c Linux-2.6.12-rc2 |
438 |
EXPORT_SYMBOL(__tasklet_schedule); |
7ad5b3a50 kernel: remove fa... |
439 |
void __tasklet_hi_schedule(struct tasklet_struct *t) |
1da177e4c Linux-2.6.12-rc2 |
440 441 442 443 |
{ unsigned long flags; local_irq_save(flags); |
48f20a9a9 tasklets: execute... |
444 |
t->next = NULL; |
909ea9646 core: Replace __g... |
445 446 |
*__this_cpu_read(tasklet_hi_vec.tail) = t; __this_cpu_write(tasklet_hi_vec.tail, &(t->next)); |
1da177e4c Linux-2.6.12-rc2 |
447 448 449 |
raise_softirq_irqoff(HI_SOFTIRQ); local_irq_restore(flags); } |
1da177e4c Linux-2.6.12-rc2 |
450 |
EXPORT_SYMBOL(__tasklet_hi_schedule); |
7c692cbad tasklets: new tas... |
451 452 453 |
void __tasklet_hi_schedule_first(struct tasklet_struct *t) { BUG_ON(!irqs_disabled()); |
909ea9646 core: Replace __g... |
454 455 |
t->next = __this_cpu_read(tasklet_hi_vec.head); __this_cpu_write(tasklet_hi_vec.head, t); |
7c692cbad tasklets: new tas... |
456 457 |
__raise_softirq_irqoff(HI_SOFTIRQ); } |
7c692cbad tasklets: new tas... |
458 |
EXPORT_SYMBOL(__tasklet_hi_schedule_first); |
1da177e4c Linux-2.6.12-rc2 |
459 460 461 462 463 |
static void tasklet_action(struct softirq_action *a) { struct tasklet_struct *list; local_irq_disable(); |
909ea9646 core: Replace __g... |
464 465 466 |
list = __this_cpu_read(tasklet_vec.head); __this_cpu_write(tasklet_vec.head, NULL); __this_cpu_write(tasklet_vec.tail, &__get_cpu_var(tasklet_vec).head); |
1da177e4c Linux-2.6.12-rc2 |
467 468 469 470 471 472 473 474 475 |
local_irq_enable(); while (list) { struct tasklet_struct *t = list; list = list->next; if (tasklet_trylock(t)) { if (!atomic_read(&t->count)) { |
ce85b4f2e softirq: use cons... |
476 477 |
if (!test_and_clear_bit(TASKLET_STATE_SCHED, &t->state)) |
1da177e4c Linux-2.6.12-rc2 |
478 479 480 481 482 483 484 485 486 |
BUG(); t->func(t->data); tasklet_unlock(t); continue; } tasklet_unlock(t); } local_irq_disable(); |
48f20a9a9 tasklets: execute... |
487 |
t->next = NULL; |
909ea9646 core: Replace __g... |
488 489 |
*__this_cpu_read(tasklet_vec.tail) = t; __this_cpu_write(tasklet_vec.tail, &(t->next)); |
1da177e4c Linux-2.6.12-rc2 |
490 491 492 493 494 495 496 497 498 499 |
__raise_softirq_irqoff(TASKLET_SOFTIRQ); local_irq_enable(); } } static void tasklet_hi_action(struct softirq_action *a) { struct tasklet_struct *list; local_irq_disable(); |
909ea9646 core: Replace __g... |
500 501 502 |
list = __this_cpu_read(tasklet_hi_vec.head); __this_cpu_write(tasklet_hi_vec.head, NULL); __this_cpu_write(tasklet_hi_vec.tail, &__get_cpu_var(tasklet_hi_vec).head); |
1da177e4c Linux-2.6.12-rc2 |
503 504 505 506 507 508 509 510 511 |
local_irq_enable(); while (list) { struct tasklet_struct *t = list; list = list->next; if (tasklet_trylock(t)) { if (!atomic_read(&t->count)) { |
ce85b4f2e softirq: use cons... |
512 513 |
if (!test_and_clear_bit(TASKLET_STATE_SCHED, &t->state)) |
1da177e4c Linux-2.6.12-rc2 |
514 515 516 517 518 519 520 521 522 |
BUG(); t->func(t->data); tasklet_unlock(t); continue; } tasklet_unlock(t); } local_irq_disable(); |
48f20a9a9 tasklets: execute... |
523 |
t->next = NULL; |
909ea9646 core: Replace __g... |
524 525 |
*__this_cpu_read(tasklet_hi_vec.tail) = t; __this_cpu_write(tasklet_hi_vec.tail, &(t->next)); |
1da177e4c Linux-2.6.12-rc2 |
526 527 528 529 |
__raise_softirq_irqoff(HI_SOFTIRQ); local_irq_enable(); } } |
1da177e4c Linux-2.6.12-rc2 |
530 531 532 533 534 535 536 537 538 |
void tasklet_init(struct tasklet_struct *t, void (*func)(unsigned long), unsigned long data) { t->next = NULL; t->state = 0; atomic_set(&t->count, 0); t->func = func; t->data = data; } |
1da177e4c Linux-2.6.12-rc2 |
539 540 541 542 543 |
EXPORT_SYMBOL(tasklet_init); void tasklet_kill(struct tasklet_struct *t) { if (in_interrupt()) |
403227641 softirq: convert ... |
544 545 |
pr_notice("Attempt to kill tasklet from interrupt "); |
1da177e4c Linux-2.6.12-rc2 |
546 547 |
while (test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) { |
79d381c9f kernel/softirq.c:... |
548 |
do { |
1da177e4c Linux-2.6.12-rc2 |
549 |
yield(); |
79d381c9f kernel/softirq.c:... |
550 |
} while (test_bit(TASKLET_STATE_SCHED, &t->state)); |
1da177e4c Linux-2.6.12-rc2 |
551 552 553 554 |
} tasklet_unlock_wait(t); clear_bit(TASKLET_STATE_SCHED, &t->state); } |
1da177e4c Linux-2.6.12-rc2 |
555 |
EXPORT_SYMBOL(tasklet_kill); |
9ba5f005c softirq: introduc... |
556 557 558 559 560 |
/* * tasklet_hrtimer */ /* |
b9c303227 hrtimer, softirq:... |
561 562 563 |
* The trampoline is called when the hrtimer expires. It schedules a tasklet * to run __tasklet_hrtimer_trampoline() which in turn will call the intended * hrtimer callback, but from softirq context. |
9ba5f005c softirq: introduc... |
564 565 566 567 568 |
*/ static enum hrtimer_restart __hrtimer_tasklet_trampoline(struct hrtimer *timer) { struct tasklet_hrtimer *ttimer = container_of(timer, struct tasklet_hrtimer, timer); |
b9c303227 hrtimer, softirq:... |
569 570 |
tasklet_hi_schedule(&ttimer->tasklet); return HRTIMER_NORESTART; |
9ba5f005c softirq: introduc... |
571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 |
} /* * Helper function which calls the hrtimer callback from * tasklet/softirq context */ static void __tasklet_hrtimer_trampoline(unsigned long data) { struct tasklet_hrtimer *ttimer = (void *)data; enum hrtimer_restart restart; restart = ttimer->function(&ttimer->timer); if (restart != HRTIMER_NORESTART) hrtimer_restart(&ttimer->timer); } /** * tasklet_hrtimer_init - Init a tasklet/hrtimer combo for softirq callbacks * @ttimer: tasklet_hrtimer which is initialized |
25985edce Fix common misspe... |
590 |
* @function: hrtimer callback function which gets called from softirq context |
9ba5f005c softirq: introduc... |
591 592 593 594 595 596 597 598 599 600 601 602 603 604 |
* @which_clock: clock id (CLOCK_MONOTONIC/CLOCK_REALTIME) * @mode: hrtimer mode (HRTIMER_MODE_ABS/HRTIMER_MODE_REL) */ void tasklet_hrtimer_init(struct tasklet_hrtimer *ttimer, enum hrtimer_restart (*function)(struct hrtimer *), clockid_t which_clock, enum hrtimer_mode mode) { hrtimer_init(&ttimer->timer, which_clock, mode); ttimer->timer.function = __hrtimer_tasklet_trampoline; tasklet_init(&ttimer->tasklet, __tasklet_hrtimer_trampoline, (unsigned long)ttimer); ttimer->function = function; } EXPORT_SYMBOL_GPL(tasklet_hrtimer_init); |
1da177e4c Linux-2.6.12-rc2 |
605 606 |
void __init softirq_init(void) { |
48f20a9a9 tasklets: execute... |
607 608 609 610 611 612 613 614 |
int cpu; for_each_possible_cpu(cpu) { per_cpu(tasklet_vec, cpu).tail = &per_cpu(tasklet_vec, cpu).head; per_cpu(tasklet_hi_vec, cpu).tail = &per_cpu(tasklet_hi_vec, cpu).head; } |
962cf36c5 Remove argument f... |
615 616 |
open_softirq(TASKLET_SOFTIRQ, tasklet_action); open_softirq(HI_SOFTIRQ, tasklet_hi_action); |
1da177e4c Linux-2.6.12-rc2 |
617 |
} |
3e339b5da softirq: Use hotp... |
618 |
static int ksoftirqd_should_run(unsigned int cpu) |
1da177e4c Linux-2.6.12-rc2 |
619 |
{ |
3e339b5da softirq: Use hotp... |
620 621 |
return local_softirq_pending(); } |
1da177e4c Linux-2.6.12-rc2 |
622 |
|
3e339b5da softirq: Use hotp... |
623 624 625 626 |
static void run_ksoftirqd(unsigned int cpu) { local_irq_disable(); if (local_softirq_pending()) { |
0bed698a3 irq: Justify the ... |
627 628 629 630 |
/* * We can safely run softirq on inline stack, as we are not deep * in the task stack here. */ |
3e339b5da softirq: Use hotp... |
631 632 633 634 635 |
__do_softirq(); rcu_note_context_switch(cpu); local_irq_enable(); cond_resched(); return; |
1da177e4c Linux-2.6.12-rc2 |
636 |
} |
3e339b5da softirq: Use hotp... |
637 |
local_irq_enable(); |
1da177e4c Linux-2.6.12-rc2 |
638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 |
} #ifdef CONFIG_HOTPLUG_CPU /* * tasklet_kill_immediate is called to remove a tasklet which can already be * scheduled for execution on @cpu. * * Unlike tasklet_kill, this function removes the tasklet * _immediately_, even if the tasklet is in TASKLET_STATE_SCHED state. * * When this function is called, @cpu must be in the CPU_DEAD state. */ void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu) { struct tasklet_struct **i; BUG_ON(cpu_online(cpu)); BUG_ON(test_bit(TASKLET_STATE_RUN, &t->state)); if (!test_bit(TASKLET_STATE_SCHED, &t->state)) return; /* CPU is dead, so no lock needed. */ |
48f20a9a9 tasklets: execute... |
661 |
for (i = &per_cpu(tasklet_vec, cpu).head; *i; i = &(*i)->next) { |
1da177e4c Linux-2.6.12-rc2 |
662 663 |
if (*i == t) { *i = t->next; |
48f20a9a9 tasklets: execute... |
664 665 666 |
/* If this was the tail element, move the tail ptr */ if (*i == NULL) per_cpu(tasklet_vec, cpu).tail = i; |
1da177e4c Linux-2.6.12-rc2 |
667 668 669 670 671 672 673 674 |
return; } } BUG(); } static void takeover_tasklets(unsigned int cpu) { |
1da177e4c Linux-2.6.12-rc2 |
675 676 677 678 |
/* CPU is dead, so no lock needed. */ local_irq_disable(); /* Find end, append list for that CPU. */ |
e5e417232 Fix cpu hotplug p... |
679 |
if (&per_cpu(tasklet_vec, cpu).head != per_cpu(tasklet_vec, cpu).tail) { |
909ea9646 core: Replace __g... |
680 681 |
*__this_cpu_read(tasklet_vec.tail) = per_cpu(tasklet_vec, cpu).head; this_cpu_write(tasklet_vec.tail, per_cpu(tasklet_vec, cpu).tail); |
e5e417232 Fix cpu hotplug p... |
682 683 684 |
per_cpu(tasklet_vec, cpu).head = NULL; per_cpu(tasklet_vec, cpu).tail = &per_cpu(tasklet_vec, cpu).head; } |
1da177e4c Linux-2.6.12-rc2 |
685 |
raise_softirq_irqoff(TASKLET_SOFTIRQ); |
e5e417232 Fix cpu hotplug p... |
686 |
if (&per_cpu(tasklet_hi_vec, cpu).head != per_cpu(tasklet_hi_vec, cpu).tail) { |
909ea9646 core: Replace __g... |
687 688 |
*__this_cpu_read(tasklet_hi_vec.tail) = per_cpu(tasklet_hi_vec, cpu).head; __this_cpu_write(tasklet_hi_vec.tail, per_cpu(tasklet_hi_vec, cpu).tail); |
e5e417232 Fix cpu hotplug p... |
689 690 691 |
per_cpu(tasklet_hi_vec, cpu).head = NULL; per_cpu(tasklet_hi_vec, cpu).tail = &per_cpu(tasklet_hi_vec, cpu).head; } |
1da177e4c Linux-2.6.12-rc2 |
692 693 694 695 696 |
raise_softirq_irqoff(HI_SOFTIRQ); local_irq_enable(); } #endif /* CONFIG_HOTPLUG_CPU */ |
ce85b4f2e softirq: use cons... |
697 698 |
static int cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) |
1da177e4c Linux-2.6.12-rc2 |
699 |
{ |
1da177e4c Linux-2.6.12-rc2 |
700 |
switch (action) { |
1da177e4c Linux-2.6.12-rc2 |
701 |
#ifdef CONFIG_HOTPLUG_CPU |
1da177e4c Linux-2.6.12-rc2 |
702 |
case CPU_DEAD: |
3e339b5da softirq: Use hotp... |
703 704 |
case CPU_DEAD_FROZEN: takeover_tasklets((unsigned long)hcpu); |
1da177e4c Linux-2.6.12-rc2 |
705 706 |
break; #endif /* CONFIG_HOTPLUG_CPU */ |
3e339b5da softirq: Use hotp... |
707 |
} |
1da177e4c Linux-2.6.12-rc2 |
708 709 |
return NOTIFY_OK; } |
0db0628d9 kernel: delete __... |
710 |
static struct notifier_block cpu_nfb = { |
1da177e4c Linux-2.6.12-rc2 |
711 712 |
.notifier_call = cpu_callback }; |
3e339b5da softirq: Use hotp... |
713 714 715 716 717 718 |
static struct smp_hotplug_thread softirq_threads = { .store = &ksoftirqd, .thread_should_run = ksoftirqd_should_run, .thread_fn = run_ksoftirqd, .thread_comm = "ksoftirqd/%u", }; |
7babe8db9 Full conversion t... |
719 |
static __init int spawn_ksoftirqd(void) |
1da177e4c Linux-2.6.12-rc2 |
720 |
{ |
1da177e4c Linux-2.6.12-rc2 |
721 |
register_cpu_notifier(&cpu_nfb); |
3e339b5da softirq: Use hotp... |
722 723 |
BUG_ON(smpboot_register_percpu_thread(&softirq_threads)); |
1da177e4c Linux-2.6.12-rc2 |
724 725 |
return 0; } |
7babe8db9 Full conversion t... |
726 |
early_initcall(spawn_ksoftirqd); |
78eef01b0 [PATCH] on_each_c... |
727 |
|
43a256322 sparseirq: move _... |
728 729 730 731 732 733 734 735 736 |
/* * [ These __weak aliases are kept in a separate compilation unit, so that * GCC does not inline them incorrectly. ] */ int __init __weak early_irq_init(void) { return 0; } |
4a046d175 x86: arch_probe_n... |
737 738 |
int __init __weak arch_probe_nr_irqs(void) { |
b683de2b3 genirq: Query arc... |
739 |
return NR_IRQS_LEGACY; |
4a046d175 x86: arch_probe_n... |
740 |
} |
43a256322 sparseirq: move _... |
741 742 743 744 |
int __init __weak arch_early_irq_init(void) { return 0; } |