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kernel/kthread.c
36.7 KB
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// SPDX-License-Identifier: GPL-2.0-only |
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/* Kernel thread helper functions. * Copyright (C) 2004 IBM Corporation, Rusty Russell. |
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* Copyright (C) 2009 Red Hat, Inc. |
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* |
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* Creation is done via kthreadd, so that we get a clean environment |
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* even if we're invoked from userspace (think modprobe, hotplug cpu, * etc.). */ |
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#include <uapi/linux/sched/types.h> |
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#include <linux/mm.h> #include <linux/mmu_context.h> |
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#include <linux/sched.h> |
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#include <linux/sched/mm.h> |
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#include <linux/sched/task.h> |
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#include <linux/kthread.h> #include <linux/completion.h> #include <linux/err.h> |
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#include <linux/cgroup.h> |
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#include <linux/cpuset.h> |
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#include <linux/unistd.h> #include <linux/file.h> |
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#include <linux/export.h> |
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#include <linux/mutex.h> |
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#include <linux/slab.h> #include <linux/freezer.h> |
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#include <linux/ptrace.h> |
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#include <linux/uaccess.h> |
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#include <linux/numa.h> |
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#include <linux/sched/isolation.h> |
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#include <trace/events/sched.h> |
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static DEFINE_SPINLOCK(kthread_create_lock); static LIST_HEAD(kthread_create_list); struct task_struct *kthreadd_task; |
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struct kthread_create_info { |
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/* Information passed to kthread() from kthreadd. */ |
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int (*threadfn)(void *data); void *data; |
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int node; |
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|
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/* Result passed back to kthread_create() from kthreadd. */ |
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struct task_struct *result; |
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struct completion *done; |
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|
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struct list_head list; |
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}; |
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struct kthread { |
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unsigned long flags; unsigned int cpu; |
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int (*threadfn)(void *); |
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void *data; |
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mm_segment_t oldfs; |
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struct completion parked; |
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struct completion exited; |
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#ifdef CONFIG_BLK_CGROUP |
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struct cgroup_subsys_state *blkcg_css; #endif |
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}; |
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enum KTHREAD_BITS { KTHREAD_IS_PER_CPU = 0, KTHREAD_SHOULD_STOP, KTHREAD_SHOULD_PARK, |
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}; |
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static inline void set_kthread_struct(void *kthread) { /* * We abuse ->set_child_tid to avoid the new member and because it * can't be wrongly copied by copy_process(). We also rely on fact * that the caller can't exec, so PF_KTHREAD can't be cleared. */ current->set_child_tid = (__force void __user *)kthread; } |
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static inline struct kthread *to_kthread(struct task_struct *k) { |
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WARN_ON(!(k->flags & PF_KTHREAD)); return (__force void *)k->set_child_tid; |
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} |
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void free_kthread_struct(struct task_struct *k) { |
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struct kthread *kthread; |
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/* * Can be NULL if this kthread was created by kernel_thread() * or if kmalloc() in kthread() failed. */ |
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kthread = to_kthread(k); |
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#ifdef CONFIG_BLK_CGROUP |
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WARN_ON_ONCE(kthread && kthread->blkcg_css); #endif kfree(kthread); |
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} |
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/** * kthread_should_stop - should this kthread return now? * |
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* When someone calls kthread_stop() on your kthread, it will be woken |
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* and this will return true. You should then return, and your return * value will be passed through to kthread_stop(). */ |
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bool kthread_should_stop(void) |
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{ |
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return test_bit(KTHREAD_SHOULD_STOP, &to_kthread(current)->flags); |
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} EXPORT_SYMBOL(kthread_should_stop); |
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bool __kthread_should_park(struct task_struct *k) { return test_bit(KTHREAD_SHOULD_PARK, &to_kthread(k)->flags); } EXPORT_SYMBOL_GPL(__kthread_should_park); |
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/** |
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* kthread_should_park - should this kthread park now? * * When someone calls kthread_park() on your kthread, it will be woken * and this will return true. You should then do the necessary * cleanup and call kthread_parkme() * * Similar to kthread_should_stop(), but this keeps the thread alive * and in a park position. kthread_unpark() "restarts" the thread and * calls the thread function again. */ bool kthread_should_park(void) { |
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return __kthread_should_park(current); |
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} |
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EXPORT_SYMBOL_GPL(kthread_should_park); |
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/** |
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* kthread_freezable_should_stop - should this freezable kthread return now? * @was_frozen: optional out parameter, indicates whether %current was frozen * * kthread_should_stop() for freezable kthreads, which will enter * refrigerator if necessary. This function is safe from kthread_stop() / * freezer deadlock and freezable kthreads should use this function instead * of calling try_to_freeze() directly. */ bool kthread_freezable_should_stop(bool *was_frozen) { bool frozen = false; might_sleep(); if (unlikely(freezing(current))) frozen = __refrigerator(true); if (was_frozen) *was_frozen = frozen; return kthread_should_stop(); } EXPORT_SYMBOL_GPL(kthread_freezable_should_stop); /** |
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* kthread_func - return the function specified on kthread creation * @task: kthread task in question * * Returns NULL if the task is not a kthread. */ void *kthread_func(struct task_struct *task) { if (task->flags & PF_KTHREAD) return to_kthread(task)->threadfn; return NULL; } EXPORT_SYMBOL_GPL(kthread_func); /** |
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* kthread_data - return data value specified on kthread creation * @task: kthread task in question * * Return the data value specified when kthread @task was created. * The caller is responsible for ensuring the validity of @task when * calling this function. */ void *kthread_data(struct task_struct *task) { return to_kthread(task)->data; } |
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EXPORT_SYMBOL_GPL(kthread_data); |
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/** |
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* kthread_probe_data - speculative version of kthread_data() |
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* @task: possible kthread task in question * * @task could be a kthread task. Return the data value specified when it * was created if accessible. If @task isn't a kthread task or its data is * inaccessible for any reason, %NULL is returned. This function requires * that @task itself is safe to dereference. */ |
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void *kthread_probe_data(struct task_struct *task) |
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{ struct kthread *kthread = to_kthread(task); void *data = NULL; |
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copy_from_kernel_nofault(&data, &kthread->data, sizeof(data)); |
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return data; } |
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static void __kthread_parkme(struct kthread *self) { |
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for (;;) { |
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/* * TASK_PARKED is a special state; we must serialize against * possible pending wakeups to avoid store-store collisions on * task->state. * * Such a collision might possibly result in the task state * changin from TASK_PARKED and us failing the * wait_task_inactive() in kthread_park(). */ set_special_state(TASK_PARKED); |
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if (!test_bit(KTHREAD_SHOULD_PARK, &self->flags)) break; |
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/* * Thread is going to call schedule(), do not preempt it, * or the caller of kthread_park() may spend more time in * wait_task_inactive(). */ preempt_disable(); |
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complete(&self->parked); |
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schedule_preempt_disabled(); preempt_enable(); |
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} |
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__set_current_state(TASK_RUNNING); } void kthread_parkme(void) { __kthread_parkme(to_kthread(current)); } |
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EXPORT_SYMBOL_GPL(kthread_parkme); |
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static int kthread(void *_create) { |
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/* Copy data: it's on kthread's stack */ |
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struct kthread_create_info *create = _create; |
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int (*threadfn)(void *data) = create->threadfn; void *data = create->data; |
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struct completion *done; |
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struct kthread *self; |
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int ret; |
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|
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self = kzalloc(sizeof(*self), GFP_KERNEL); |
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set_kthread_struct(self); |
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|
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/* If user was SIGKILLed, I release the structure. */ done = xchg(&create->done, NULL); if (!done) { kfree(create); do_exit(-EINTR); } |
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if (!self) { create->result = ERR_PTR(-ENOMEM); complete(done); do_exit(-ENOMEM); } |
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self->threadfn = threadfn; |
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self->data = data; init_completion(&self->exited); init_completion(&self->parked); current->vfork_done = &self->exited; |
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/* OK, tell user we're spawned, wait for stop or wakeup */ |
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__set_current_state(TASK_UNINTERRUPTIBLE); |
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create->result = current; |
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/* * Thread is going to call schedule(), do not preempt it, * or the creator may spend more time in wait_task_inactive(). */ preempt_disable(); |
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complete(done); |
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schedule_preempt_disabled(); preempt_enable(); |
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|
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ret = -EINTR; |
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if (!test_bit(KTHREAD_SHOULD_STOP, &self->flags)) { |
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cgroup_kthread_ready(); |
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__kthread_parkme(self); |
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ret = threadfn(data); } |
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do_exit(ret); |
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} |
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/* called from do_fork() to get node information for about to be created task */ int tsk_fork_get_node(struct task_struct *tsk) { #ifdef CONFIG_NUMA if (tsk == kthreadd_task) return tsk->pref_node_fork; #endif |
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return NUMA_NO_NODE; |
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} |
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static void create_kthread(struct kthread_create_info *create) |
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{ |
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int pid; |
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#ifdef CONFIG_NUMA current->pref_node_fork = create->node; #endif |
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/* We want our own signal handler (we take no signals by default). */ pid = kernel_thread(kthread, create, CLONE_FS | CLONE_FILES | SIGCHLD); |
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if (pid < 0) { |
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/* If user was SIGKILLed, I release the structure. */ struct completion *done = xchg(&create->done, NULL); if (!done) { kfree(create); return; } |
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create->result = ERR_PTR(pid); |
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complete(done); |
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} |
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} |
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static __printf(4, 0) struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data), |
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void *data, int node, const char namefmt[], va_list args) |
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{ |
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DECLARE_COMPLETION_ONSTACK(done); struct task_struct *task; struct kthread_create_info *create = kmalloc(sizeof(*create), GFP_KERNEL); if (!create) return ERR_PTR(-ENOMEM); create->threadfn = threadfn; create->data = data; create->node = node; create->done = &done; |
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spin_lock(&kthread_create_lock); |
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list_add_tail(&create->list, &kthread_create_list); |
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spin_unlock(&kthread_create_lock); |
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wake_up_process(kthreadd_task); |
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/* * Wait for completion in killable state, for I might be chosen by * the OOM killer while kthreadd is trying to allocate memory for * new kernel thread. */ if (unlikely(wait_for_completion_killable(&done))) { /* * If I was SIGKILLed before kthreadd (or new kernel thread) * calls complete(), leave the cleanup of this structure to * that thread. */ if (xchg(&create->done, NULL)) |
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return ERR_PTR(-EINTR); |
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/* * kthreadd (or new kernel thread) will call complete() * shortly. */ wait_for_completion(&done); } task = create->result; if (!IS_ERR(task)) { |
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static const struct sched_param param = { .sched_priority = 0 }; |
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char name[TASK_COMM_LEN]; |
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|
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/* * task is already visible to other tasks, so updating * COMM must be protected. */ vsnprintf(name, sizeof(name), namefmt, args); set_task_comm(task, name); |
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/* * root may have changed our (kthreadd's) priority or CPU mask. * The kernel thread should not inherit these properties. */ |
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sched_setscheduler_nocheck(task, SCHED_NORMAL, ¶m); |
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set_cpus_allowed_ptr(task, housekeeping_cpumask(HK_FLAG_KTHREAD)); |
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} |
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kfree(create); return task; |
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} |
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/** * kthread_create_on_node - create a kthread. * @threadfn: the function to run until signal_pending(current). * @data: data ptr for @threadfn. * @node: task and thread structures for the thread are allocated on this node * @namefmt: printf-style name for the thread. * * Description: This helper function creates and names a kernel * thread. The thread will be stopped: use wake_up_process() to start * it. See also kthread_run(). The new thread has SCHED_NORMAL policy and * is affine to all CPUs. * * If thread is going to be bound on a particular cpu, give its node * in @node, to get NUMA affinity for kthread stack, or else give NUMA_NO_NODE. * When woken, the thread will run @threadfn() with @data as its * argument. @threadfn() can either call do_exit() directly if it is a * standalone thread for which no one will call kthread_stop(), or * return when 'kthread_should_stop()' is true (which means * kthread_stop() has been called). The return value should be zero * or a negative error number; it will be passed to kthread_stop(). * * Returns a task_struct or ERR_PTR(-ENOMEM) or ERR_PTR(-EINTR). */ struct task_struct *kthread_create_on_node(int (*threadfn)(void *data), void *data, int node, const char namefmt[], ...) { struct task_struct *task; va_list args; va_start(args, namefmt); task = __kthread_create_on_node(threadfn, data, node, namefmt, args); va_end(args); return task; } |
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EXPORT_SYMBOL(kthread_create_on_node); |
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|
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static void __kthread_bind_mask(struct task_struct *p, const struct cpumask *mask, long state) |
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{ |
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unsigned long flags; |
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if (!wait_task_inactive(p, state)) { WARN_ON(1); return; } |
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|
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/* It's safe because the task is inactive. */ |
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raw_spin_lock_irqsave(&p->pi_lock, flags); do_set_cpus_allowed(p, mask); |
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p->flags |= PF_NO_SETAFFINITY; |
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raw_spin_unlock_irqrestore(&p->pi_lock, flags); } static void __kthread_bind(struct task_struct *p, unsigned int cpu, long state) { __kthread_bind_mask(p, cpumask_of(cpu), state); } void kthread_bind_mask(struct task_struct *p, const struct cpumask *mask) { __kthread_bind_mask(p, mask, TASK_UNINTERRUPTIBLE); |
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} |
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EXPORT_SYMBOL_GPL(kthread_bind_mask); |
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|
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/** |
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* kthread_bind - bind a just-created kthread to a cpu. * @p: thread created by kthread_create(). * @cpu: cpu (might not be online, must be possible) for @k to run on. * * Description: This function is equivalent to set_cpus_allowed(), * except that @cpu doesn't need to be online, and the thread must be * stopped (i.e., just returned from kthread_create()). */ void kthread_bind(struct task_struct *p, unsigned int cpu) { |
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__kthread_bind(p, cpu, TASK_UNINTERRUPTIBLE); |
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} EXPORT_SYMBOL(kthread_bind); /** |
2a1d44601 kthread: Implemen... |
458 459 460 461 462 463 464 465 |
* kthread_create_on_cpu - Create a cpu bound kthread * @threadfn: the function to run until signal_pending(current). * @data: data ptr for @threadfn. * @cpu: The cpu on which the thread should be bound, * @namefmt: printf-style name for the thread. Format is restricted * to "name.*%u". Code fills in cpu number. * * Description: This helper function creates and names a kernel thread |
2a1d44601 kthread: Implemen... |
466 467 468 469 470 471 |
*/ struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data), void *data, unsigned int cpu, const char *namefmt) { struct task_struct *p; |
109228389 kernel/kthread.c:... |
472 |
p = kthread_create_on_node(threadfn, data, cpu_to_node(cpu), namefmt, |
2a1d44601 kthread: Implemen... |
473 474 475 |
cpu); if (IS_ERR(p)) return p; |
a65d40961 kthread/smpboot: ... |
476 477 |
kthread_bind(p, cpu); /* CPU hotplug need to bind once again when unparking the thread. */ |
2a1d44601 kthread: Implemen... |
478 479 |
set_bit(KTHREAD_IS_PER_CPU, &to_kthread(p)->flags); to_kthread(p)->cpu = cpu; |
2a1d44601 kthread: Implemen... |
480 481 |
return p; } |
cf380a4a9 kthread: Don't us... |
482 483 484 485 486 487 488 489 490 |
/** * kthread_unpark - unpark a thread created by kthread_create(). * @k: thread created by kthread_create(). * * Sets kthread_should_park() for @k to return false, wakes it, and * waits for it to return. If the thread is marked percpu then its * bound to the cpu again. */ void kthread_unpark(struct task_struct *k) |
f2530dc71 kthread: Prevent ... |
491 |
{ |
cf380a4a9 kthread: Don't us... |
492 |
struct kthread *kthread = to_kthread(k); |
f2530dc71 kthread: Prevent ... |
493 |
/* |
85f1abe00 kthread, sched/wa... |
494 495 |
* Newly created kthread was parked when the CPU was offline. * The binding was lost and we need to set it again. |
f2530dc71 kthread: Prevent ... |
496 |
*/ |
85f1abe00 kthread, sched/wa... |
497 498 499 500 |
if (test_bit(KTHREAD_IS_PER_CPU, &kthread->flags)) __kthread_bind(k, kthread->cpu, TASK_PARKED); clear_bit(KTHREAD_SHOULD_PARK, &kthread->flags); |
1cef1150e kthread, sched/co... |
501 502 503 |
/* * __kthread_parkme() will either see !SHOULD_PARK or get the wakeup. */ |
85f1abe00 kthread, sched/wa... |
504 |
wake_up_state(k, TASK_PARKED); |
f2530dc71 kthread: Prevent ... |
505 |
} |
18896451e kthread: export k... |
506 |
EXPORT_SYMBOL_GPL(kthread_unpark); |
2a1d44601 kthread: Implemen... |
507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 |
/** * kthread_park - park a thread created by kthread_create(). * @k: thread created by kthread_create(). * * Sets kthread_should_park() for @k to return true, wakes it, and * waits for it to return. This can also be called after kthread_create() * instead of calling wake_up_process(): the thread will park without * calling threadfn(). * * Returns 0 if the thread is parked, -ENOSYS if the thread exited. * If called by the kthread itself just the park bit is set. */ int kthread_park(struct task_struct *k) { |
cf380a4a9 kthread: Don't us... |
522 523 524 525 |
struct kthread *kthread = to_kthread(k); if (WARN_ON(k->flags & PF_EXITING)) return -ENOSYS; |
f83ee19be kthread: Simplify... |
526 527 |
if (WARN_ON_ONCE(test_bit(KTHREAD_SHOULD_PARK, &kthread->flags))) return -EBUSY; |
85f1abe00 kthread, sched/wa... |
528 529 530 |
set_bit(KTHREAD_SHOULD_PARK, &kthread->flags); if (k != current) { wake_up_process(k); |
1cef1150e kthread, sched/co... |
531 532 533 534 |
/* * Wait for __kthread_parkme() to complete(), this means we * _will_ have TASK_PARKED and are about to call schedule(). */ |
85f1abe00 kthread, sched/wa... |
535 |
wait_for_completion(&kthread->parked); |
1cef1150e kthread, sched/co... |
536 537 538 539 540 |
/* * Now wait for that schedule() to complete and the task to * get scheduled out. */ WARN_ON_ONCE(!wait_task_inactive(k, TASK_PARKED)); |
2a1d44601 kthread: Implemen... |
541 |
} |
cf380a4a9 kthread: Don't us... |
542 543 |
return 0; |
2a1d44601 kthread: Implemen... |
544 |
} |
18896451e kthread: export k... |
545 |
EXPORT_SYMBOL_GPL(kthread_park); |
2a1d44601 kthread: Implemen... |
546 547 |
/** |
9e37bd301 [PATCH] kthread: ... |
548 549 550 551 |
* kthread_stop - stop a thread created by kthread_create(). * @k: thread created by kthread_create(). * * Sets kthread_should_stop() for @k to return true, wakes it, and |
9ae260270 update the commen... |
552 553 554 555 556 557 |
* waits for it to exit. This can also be called after kthread_create() * instead of calling wake_up_process(): the thread will exit without * calling threadfn(). * * If threadfn() may call do_exit() itself, the caller must ensure * task_struct can't go away. |
9e37bd301 [PATCH] kthread: ... |
558 559 560 561 |
* * Returns the result of threadfn(), or %-EINTR if wake_up_process() * was never called. */ |
1da177e4c Linux-2.6.12-rc2 |
562 563 |
int kthread_stop(struct task_struct *k) { |
b5c5442bb kthread: kill tas... |
564 |
struct kthread *kthread; |
1da177e4c Linux-2.6.12-rc2 |
565 |
int ret; |
0a16b6075 tracing, sched: L... |
566 |
trace_sched_kthread_stop(k); |
b5c5442bb kthread: kill tas... |
567 568 |
get_task_struct(k); |
efb29fbfa kthread: Don't us... |
569 570 |
kthread = to_kthread(k); set_bit(KTHREAD_SHOULD_STOP, &kthread->flags); |
cf380a4a9 kthread: Don't us... |
571 |
kthread_unpark(k); |
efb29fbfa kthread: Don't us... |
572 573 |
wake_up_process(k); wait_for_completion(&kthread->exited); |
63706172f kthreads: rework ... |
574 |
ret = k->exit_code; |
1da177e4c Linux-2.6.12-rc2 |
575 |
put_task_struct(k); |
0a16b6075 tracing, sched: L... |
576 |
|
b5c5442bb kthread: kill tas... |
577 |
trace_sched_kthread_stop_ret(ret); |
1da177e4c Linux-2.6.12-rc2 |
578 579 |
return ret; } |
52e92e578 [PATCH] remove ke... |
580 |
EXPORT_SYMBOL(kthread_stop); |
1da177e4c Linux-2.6.12-rc2 |
581 |
|
e804a4a4d kthread: silence ... |
582 |
int kthreadd(void *unused) |
1da177e4c Linux-2.6.12-rc2 |
583 |
{ |
73c279927 kthread: don't de... |
584 |
struct task_struct *tsk = current; |
1da177e4c Linux-2.6.12-rc2 |
585 |
|
e804a4a4d kthread: silence ... |
586 |
/* Setup a clean context for our children to inherit. */ |
73c279927 kthread: don't de... |
587 |
set_task_comm(tsk, "kthreadd"); |
10ab825bd change kernel thr... |
588 |
ignore_signals(tsk); |
9cc5b8656 isolcpus: Affine ... |
589 |
set_cpus_allowed_ptr(tsk, housekeeping_cpumask(HK_FLAG_KTHREAD)); |
aee4faa49 kthread: use N_ME... |
590 |
set_mems_allowed(node_states[N_MEMORY]); |
73c279927 kthread: don't de... |
591 |
|
34b087e48 freezer: kill unu... |
592 |
current->flags |= PF_NOFREEZE; |
77f88796c cgroup, kthread: ... |
593 |
cgroup_init_kthreadd(); |
73c279927 kthread: don't de... |
594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 |
for (;;) { set_current_state(TASK_INTERRUPTIBLE); if (list_empty(&kthread_create_list)) schedule(); __set_current_state(TASK_RUNNING); spin_lock(&kthread_create_lock); while (!list_empty(&kthread_create_list)) { struct kthread_create_info *create; create = list_entry(kthread_create_list.next, struct kthread_create_info, list); list_del_init(&create->list); spin_unlock(&kthread_create_lock); create_kthread(create); spin_lock(&kthread_create_lock); } spin_unlock(&kthread_create_lock); } return 0; } |
b56c0d893 kthread: implemen... |
619 |
|
3989144f8 kthread: kthread ... |
620 |
void __kthread_init_worker(struct kthread_worker *worker, |
4f32e9b1f kthread_work: mak... |
621 622 623 |
const char *name, struct lock_class_key *key) { |
dbf52682c kthread: better s... |
624 |
memset(worker, 0, sizeof(struct kthread_worker)); |
fe99a4f4d kthread: Convert ... |
625 |
raw_spin_lock_init(&worker->lock); |
4f32e9b1f kthread_work: mak... |
626 627 |
lockdep_set_class_and_name(&worker->lock, key, name); INIT_LIST_HEAD(&worker->work_list); |
22597dc3d kthread: initial ... |
628 |
INIT_LIST_HEAD(&worker->delayed_work_list); |
4f32e9b1f kthread_work: mak... |
629 |
} |
3989144f8 kthread: kthread ... |
630 |
EXPORT_SYMBOL_GPL(__kthread_init_worker); |
4f32e9b1f kthread_work: mak... |
631 |
|
b56c0d893 kthread: implemen... |
632 633 634 635 |
/** * kthread_worker_fn - kthread function to process kthread_worker * @worker_ptr: pointer to initialized kthread_worker * |
fbae2d44a kthread: add kthr... |
636 637 638 |
* This function implements the main cycle of kthread worker. It processes * work_list until it is stopped with kthread_stop(). It sleeps when the queue * is empty. |
b56c0d893 kthread: implemen... |
639 |
* |
fbae2d44a kthread: add kthr... |
640 641 642 |
* The works are not allowed to keep any locks, disable preemption or interrupts * when they finish. There is defined a safe point for freezing when one work * finishes and before a new one is started. |
8197b3d43 kthread: detect w... |
643 644 645 |
* * Also the works must not be handled by more than one worker at the same time, * see also kthread_queue_work(). |
b56c0d893 kthread: implemen... |
646 647 648 649 650 |
*/ int kthread_worker_fn(void *worker_ptr) { struct kthread_worker *worker = worker_ptr; struct kthread_work *work; |
fbae2d44a kthread: add kthr... |
651 652 653 654 655 |
/* * FIXME: Update the check and remove the assignment when all kthread * worker users are created using kthread_create_worker*() functions. */ WARN_ON(worker->task && worker->task != current); |
b56c0d893 kthread: implemen... |
656 |
worker->task = current; |
dbf52682c kthread: better s... |
657 658 659 |
if (worker->flags & KTW_FREEZABLE) set_freezable(); |
b56c0d893 kthread: implemen... |
660 661 662 663 664 |
repeat: set_current_state(TASK_INTERRUPTIBLE); /* mb paired w/ kthread_stop */ if (kthread_should_stop()) { __set_current_state(TASK_RUNNING); |
fe99a4f4d kthread: Convert ... |
665 |
raw_spin_lock_irq(&worker->lock); |
b56c0d893 kthread: implemen... |
666 |
worker->task = NULL; |
fe99a4f4d kthread: Convert ... |
667 |
raw_spin_unlock_irq(&worker->lock); |
b56c0d893 kthread: implemen... |
668 669 670 671 |
return 0; } work = NULL; |
fe99a4f4d kthread: Convert ... |
672 |
raw_spin_lock_irq(&worker->lock); |
b56c0d893 kthread: implemen... |
673 674 675 676 677 |
if (!list_empty(&worker->work_list)) { work = list_first_entry(&worker->work_list, struct kthread_work, node); list_del_init(&work->node); } |
46f3d9762 kthread_worker: r... |
678 |
worker->current_work = work; |
fe99a4f4d kthread: Convert ... |
679 |
raw_spin_unlock_irq(&worker->lock); |
b56c0d893 kthread: implemen... |
680 681 682 683 |
if (work) { __set_current_state(TASK_RUNNING); work->func(work); |
b56c0d893 kthread: implemen... |
684 685 686 687 |
} else if (!freezing(current)) schedule(); try_to_freeze(); |
22cf8bc6c kernel/kthread.c:... |
688 |
cond_resched(); |
b56c0d893 kthread: implemen... |
689 690 691 |
goto repeat; } EXPORT_SYMBOL_GPL(kthread_worker_fn); |
c0b942a76 kthread: add __pr... |
692 |
static __printf(3, 0) struct kthread_worker * |
dbf52682c kthread: better s... |
693 694 |
__kthread_create_worker(int cpu, unsigned int flags, const char namefmt[], va_list args) |
fbae2d44a kthread: add kthr... |
695 696 697 |
{ struct kthread_worker *worker; struct task_struct *task; |
98fa15f34 mm: replace all o... |
698 |
int node = NUMA_NO_NODE; |
fbae2d44a kthread: add kthr... |
699 700 701 702 703 704 |
worker = kzalloc(sizeof(*worker), GFP_KERNEL); if (!worker) return ERR_PTR(-ENOMEM); kthread_init_worker(worker); |
8fb9dcbdc kthread: Don't ab... |
705 706 |
if (cpu >= 0) node = cpu_to_node(cpu); |
fbae2d44a kthread: add kthr... |
707 |
|
8fb9dcbdc kthread: Don't ab... |
708 709 |
task = __kthread_create_on_node(kthread_worker_fn, worker, node, namefmt, args); |
fbae2d44a kthread: add kthr... |
710 711 |
if (IS_ERR(task)) goto fail_task; |
8fb9dcbdc kthread: Don't ab... |
712 713 |
if (cpu >= 0) kthread_bind(task, cpu); |
dbf52682c kthread: better s... |
714 |
worker->flags = flags; |
fbae2d44a kthread: add kthr... |
715 716 717 718 719 720 721 722 723 724 725 |
worker->task = task; wake_up_process(task); return worker; fail_task: kfree(worker); return ERR_CAST(task); } /** * kthread_create_worker - create a kthread worker |
dbf52682c kthread: better s... |
726 |
* @flags: flags modifying the default behavior of the worker |
fbae2d44a kthread: add kthr... |
727 728 729 730 731 732 733 |
* @namefmt: printf-style name for the kthread worker (task). * * Returns a pointer to the allocated worker on success, ERR_PTR(-ENOMEM) * when the needed structures could not get allocated, and ERR_PTR(-EINTR) * when the worker was SIGKILLed. */ struct kthread_worker * |
dbf52682c kthread: better s... |
734 |
kthread_create_worker(unsigned int flags, const char namefmt[], ...) |
fbae2d44a kthread: add kthr... |
735 736 737 738 739 |
{ struct kthread_worker *worker; va_list args; va_start(args, namefmt); |
dbf52682c kthread: better s... |
740 |
worker = __kthread_create_worker(-1, flags, namefmt, args); |
fbae2d44a kthread: add kthr... |
741 742 743 744 745 746 747 748 |
va_end(args); return worker; } EXPORT_SYMBOL(kthread_create_worker); /** * kthread_create_worker_on_cpu - create a kthread worker and bind it |
7b7b8a2c9 kernel/: fix repe... |
749 |
* to a given CPU and the associated NUMA node. |
fbae2d44a kthread: add kthr... |
750 |
* @cpu: CPU number |
dbf52682c kthread: better s... |
751 |
* @flags: flags modifying the default behavior of the worker |
fbae2d44a kthread: add kthr... |
752 753 754 755 756 757 758 759 760 761 762 763 764 |
* @namefmt: printf-style name for the kthread worker (task). * * Use a valid CPU number if you want to bind the kthread worker * to the given CPU and the associated NUMA node. * * A good practice is to add the cpu number also into the worker name. * For example, use kthread_create_worker_on_cpu(cpu, "helper/%d", cpu). * * Returns a pointer to the allocated worker on success, ERR_PTR(-ENOMEM) * when the needed structures could not get allocated, and ERR_PTR(-EINTR) * when the worker was SIGKILLed. */ struct kthread_worker * |
dbf52682c kthread: better s... |
765 766 |
kthread_create_worker_on_cpu(int cpu, unsigned int flags, const char namefmt[], ...) |
fbae2d44a kthread: add kthr... |
767 768 769 770 771 |
{ struct kthread_worker *worker; va_list args; va_start(args, namefmt); |
dbf52682c kthread: better s... |
772 |
worker = __kthread_create_worker(cpu, flags, namefmt, args); |
fbae2d44a kthread: add kthr... |
773 774 775 776 777 |
va_end(args); return worker; } EXPORT_SYMBOL(kthread_create_worker_on_cpu); |
37be45d49 kthread: allow to... |
778 779 780 781 782 783 784 785 786 787 788 789 |
/* * Returns true when the work could not be queued at the moment. * It happens when it is already pending in a worker list * or when it is being cancelled. */ static inline bool queuing_blocked(struct kthread_worker *worker, struct kthread_work *work) { lockdep_assert_held(&worker->lock); return !list_empty(&work->node) || work->canceling; } |
8197b3d43 kthread: detect w... |
790 791 792 793 794 795 796 797 |
static void kthread_insert_work_sanity_check(struct kthread_worker *worker, struct kthread_work *work) { lockdep_assert_held(&worker->lock); WARN_ON_ONCE(!list_empty(&work->node)); /* Do not use a work with >1 worker, see kthread_queue_work() */ WARN_ON_ONCE(work->worker && work->worker != worker); } |
9a2e03d8e kthread_worker: r... |
798 |
/* insert @work before @pos in @worker */ |
3989144f8 kthread: kthread ... |
799 |
static void kthread_insert_work(struct kthread_worker *worker, |
8197b3d43 kthread: detect w... |
800 801 |
struct kthread_work *work, struct list_head *pos) |
9a2e03d8e kthread_worker: r... |
802 |
{ |
8197b3d43 kthread: detect w... |
803 |
kthread_insert_work_sanity_check(worker, work); |
9a2e03d8e kthread_worker: r... |
804 805 |
list_add_tail(&work->node, pos); |
46f3d9762 kthread_worker: r... |
806 |
work->worker = worker; |
ed1403ec2 kthread_work: wak... |
807 |
if (!worker->current_work && likely(worker->task)) |
9a2e03d8e kthread_worker: r... |
808 809 |
wake_up_process(worker->task); } |
b56c0d893 kthread: implemen... |
810 |
/** |
3989144f8 kthread: kthread ... |
811 |
* kthread_queue_work - queue a kthread_work |
b56c0d893 kthread: implemen... |
812 813 814 815 816 817 |
* @worker: target kthread_worker * @work: kthread_work to queue * * Queue @work to work processor @task for async execution. @task * must have been created with kthread_worker_create(). Returns %true * if @work was successfully queued, %false if it was already pending. |
8197b3d43 kthread: detect w... |
818 819 820 |
* * Reinitialize the work if it needs to be used by another worker. * For example, when the worker was stopped and started again. |
b56c0d893 kthread: implemen... |
821 |
*/ |
3989144f8 kthread: kthread ... |
822 |
bool kthread_queue_work(struct kthread_worker *worker, |
b56c0d893 kthread: implemen... |
823 824 825 826 |
struct kthread_work *work) { bool ret = false; unsigned long flags; |
fe99a4f4d kthread: Convert ... |
827 |
raw_spin_lock_irqsave(&worker->lock, flags); |
37be45d49 kthread: allow to... |
828 |
if (!queuing_blocked(worker, work)) { |
3989144f8 kthread: kthread ... |
829 |
kthread_insert_work(worker, work, &worker->work_list); |
b56c0d893 kthread: implemen... |
830 831 |
ret = true; } |
fe99a4f4d kthread: Convert ... |
832 |
raw_spin_unlock_irqrestore(&worker->lock, flags); |
b56c0d893 kthread: implemen... |
833 834 |
return ret; } |
3989144f8 kthread: kthread ... |
835 |
EXPORT_SYMBOL_GPL(kthread_queue_work); |
b56c0d893 kthread: implemen... |
836 |
|
22597dc3d kthread: initial ... |
837 838 839 |
/** * kthread_delayed_work_timer_fn - callback that queues the associated kthread * delayed work when the timer expires. |
fe5c3b69b kthread: Convert ... |
840 |
* @t: pointer to the expired timer |
22597dc3d kthread: initial ... |
841 842 843 844 |
* * The format of the function is defined by struct timer_list. * It should have been called from irqsafe timer with irq already off. */ |
fe5c3b69b kthread: Convert ... |
845 |
void kthread_delayed_work_timer_fn(struct timer_list *t) |
22597dc3d kthread: initial ... |
846 |
{ |
fe5c3b69b kthread: Convert ... |
847 |
struct kthread_delayed_work *dwork = from_timer(dwork, t, timer); |
22597dc3d kthread: initial ... |
848 849 |
struct kthread_work *work = &dwork->work; struct kthread_worker *worker = work->worker; |
ad01423ae kthread: Do not u... |
850 |
unsigned long flags; |
22597dc3d kthread: initial ... |
851 852 853 854 855 856 857 |
/* * This might happen when a pending work is reinitialized. * It means that it is used a wrong way. */ if (WARN_ON_ONCE(!worker)) return; |
ad01423ae kthread: Do not u... |
858 |
raw_spin_lock_irqsave(&worker->lock, flags); |
22597dc3d kthread: initial ... |
859 860 861 862 863 864 |
/* Work must not be used with >1 worker, see kthread_queue_work(). */ WARN_ON_ONCE(work->worker != worker); /* Move the work from worker->delayed_work_list. */ WARN_ON_ONCE(list_empty(&work->node)); list_del_init(&work->node); |
6993d0fdb kthread_worker: p... |
865 866 |
if (!work->canceling) kthread_insert_work(worker, work, &worker->work_list); |
22597dc3d kthread: initial ... |
867 |
|
ad01423ae kthread: Do not u... |
868 |
raw_spin_unlock_irqrestore(&worker->lock, flags); |
22597dc3d kthread: initial ... |
869 870 |
} EXPORT_SYMBOL(kthread_delayed_work_timer_fn); |
bc88f85c6 kthread: make __k... |
871 872 873 |
static void __kthread_queue_delayed_work(struct kthread_worker *worker, struct kthread_delayed_work *dwork, unsigned long delay) |
22597dc3d kthread: initial ... |
874 875 876 |
{ struct timer_list *timer = &dwork->timer; struct kthread_work *work = &dwork->work; |
0f186b1e6 ANDROID: kthread:... |
877 878 879 880 881 882 883 |
/* * With CFI, timer->function can point to a jump table entry in a module, * which fails the comparison. Disable the warning if CFI and modules are * both enabled. */ if (!IS_ENABLED(CONFIG_CFI_CLANG) || !IS_ENABLED(CONFIG_MODULES)) WARN_ON_ONCE(timer->function != kthread_delayed_work_timer_fn); |
22597dc3d kthread: initial ... |
884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 |
/* * If @delay is 0, queue @dwork->work immediately. This is for * both optimization and correctness. The earliest @timer can * expire is on the closest next tick and delayed_work users depend * on that there's no such delay when @delay is 0. */ if (!delay) { kthread_insert_work(worker, work, &worker->work_list); return; } /* Be paranoid and try to detect possible races already now. */ kthread_insert_work_sanity_check(worker, work); list_add(&work->node, &worker->delayed_work_list); work->worker = worker; |
22597dc3d kthread: initial ... |
901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 |
timer->expires = jiffies + delay; add_timer(timer); } /** * kthread_queue_delayed_work - queue the associated kthread work * after a delay. * @worker: target kthread_worker * @dwork: kthread_delayed_work to queue * @delay: number of jiffies to wait before queuing * * If the work has not been pending it starts a timer that will queue * the work after the given @delay. If @delay is zero, it queues the * work immediately. * * Return: %false if the @work has already been pending. It means that * either the timer was running or the work was queued. It returns %true * otherwise. */ bool kthread_queue_delayed_work(struct kthread_worker *worker, struct kthread_delayed_work *dwork, unsigned long delay) { struct kthread_work *work = &dwork->work; unsigned long flags; bool ret = false; |
fe99a4f4d kthread: Convert ... |
927 |
raw_spin_lock_irqsave(&worker->lock, flags); |
22597dc3d kthread: initial ... |
928 |
|
37be45d49 kthread: allow to... |
929 |
if (!queuing_blocked(worker, work)) { |
22597dc3d kthread: initial ... |
930 931 932 |
__kthread_queue_delayed_work(worker, dwork, delay); ret = true; } |
fe99a4f4d kthread: Convert ... |
933 |
raw_spin_unlock_irqrestore(&worker->lock, flags); |
22597dc3d kthread: initial ... |
934 935 936 |
return ret; } EXPORT_SYMBOL_GPL(kthread_queue_delayed_work); |
9a2e03d8e kthread_worker: r... |
937 938 939 940 941 942 943 944 945 946 947 |
struct kthread_flush_work { struct kthread_work work; struct completion done; }; static void kthread_flush_work_fn(struct kthread_work *work) { struct kthread_flush_work *fwork = container_of(work, struct kthread_flush_work, work); complete(&fwork->done); } |
b56c0d893 kthread: implemen... |
948 |
/** |
3989144f8 kthread: kthread ... |
949 |
* kthread_flush_work - flush a kthread_work |
b56c0d893 kthread: implemen... |
950 951 952 953 |
* @work: work to flush * * If @work is queued or executing, wait for it to finish execution. */ |
3989144f8 kthread: kthread ... |
954 |
void kthread_flush_work(struct kthread_work *work) |
b56c0d893 kthread: implemen... |
955 |
{ |
46f3d9762 kthread_worker: r... |
956 957 958 959 960 961 |
struct kthread_flush_work fwork = { KTHREAD_WORK_INIT(fwork.work, kthread_flush_work_fn), COMPLETION_INITIALIZER_ONSTACK(fwork.done), }; struct kthread_worker *worker; bool noop = false; |
46f3d9762 kthread_worker: r... |
962 963 964 |
worker = work->worker; if (!worker) return; |
b56c0d893 kthread: implemen... |
965 |
|
fe99a4f4d kthread: Convert ... |
966 |
raw_spin_lock_irq(&worker->lock); |
8197b3d43 kthread: detect w... |
967 968 |
/* Work must not be used with >1 worker, see kthread_queue_work(). */ WARN_ON_ONCE(work->worker != worker); |
b56c0d893 kthread: implemen... |
969 |
|
46f3d9762 kthread_worker: r... |
970 |
if (!list_empty(&work->node)) |
3989144f8 kthread: kthread ... |
971 |
kthread_insert_work(worker, &fwork.work, work->node.next); |
46f3d9762 kthread_worker: r... |
972 |
else if (worker->current_work == work) |
3989144f8 kthread: kthread ... |
973 974 |
kthread_insert_work(worker, &fwork.work, worker->work_list.next); |
46f3d9762 kthread_worker: r... |
975 976 |
else noop = true; |
b56c0d893 kthread: implemen... |
977 |
|
fe99a4f4d kthread: Convert ... |
978 |
raw_spin_unlock_irq(&worker->lock); |
b56c0d893 kthread: implemen... |
979 |
|
46f3d9762 kthread_worker: r... |
980 981 |
if (!noop) wait_for_completion(&fwork.done); |
b56c0d893 kthread: implemen... |
982 |
} |
3989144f8 kthread: kthread ... |
983 |
EXPORT_SYMBOL_GPL(kthread_flush_work); |
b56c0d893 kthread: implemen... |
984 |
|
37be45d49 kthread: allow to... |
985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 |
/* * This function removes the work from the worker queue. Also it makes sure * that it won't get queued later via the delayed work's timer. * * The work might still be in use when this function finishes. See the * current_work proceed by the worker. * * Return: %true if @work was pending and successfully canceled, * %false if @work was not pending */ static bool __kthread_cancel_work(struct kthread_work *work, bool is_dwork, unsigned long *flags) { /* Try to cancel the timer if exists. */ if (is_dwork) { struct kthread_delayed_work *dwork = container_of(work, struct kthread_delayed_work, work); struct kthread_worker *worker = work->worker; /* * del_timer_sync() must be called to make sure that the timer * callback is not running. The lock must be temporary released * to avoid a deadlock with the callback. In the meantime, * any queuing is blocked by setting the canceling counter. */ work->canceling++; |
fe99a4f4d kthread: Convert ... |
1011 |
raw_spin_unlock_irqrestore(&worker->lock, *flags); |
37be45d49 kthread: allow to... |
1012 |
del_timer_sync(&dwork->timer); |
fe99a4f4d kthread: Convert ... |
1013 |
raw_spin_lock_irqsave(&worker->lock, *flags); |
37be45d49 kthread: allow to... |
1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 |
work->canceling--; } /* * Try to remove the work from a worker list. It might either * be from worker->work_list or from worker->delayed_work_list. */ if (!list_empty(&work->node)) { list_del_init(&work->node); return true; } return false; } |
9a6b06c8d kthread: allow to... |
1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 |
/** * kthread_mod_delayed_work - modify delay of or queue a kthread delayed work * @worker: kthread worker to use * @dwork: kthread delayed work to queue * @delay: number of jiffies to wait before queuing * * If @dwork is idle, equivalent to kthread_queue_delayed_work(). Otherwise, * modify @dwork's timer so that it expires after @delay. If @delay is zero, * @work is guaranteed to be queued immediately. * * Return: %true if @dwork was pending and its timer was modified, * %false otherwise. * * A special case is when the work is being canceled in parallel. * It might be caused either by the real kthread_cancel_delayed_work_sync() * or yet another kthread_mod_delayed_work() call. We let the other command * win and return %false here. The caller is supposed to synchronize these * operations a reasonable way. * * This function is safe to call from any context including IRQ handler. * See __kthread_cancel_work() and kthread_delayed_work_timer_fn() * for details. */ bool kthread_mod_delayed_work(struct kthread_worker *worker, struct kthread_delayed_work *dwork, unsigned long delay) { struct kthread_work *work = &dwork->work; unsigned long flags; int ret = false; |
fe99a4f4d kthread: Convert ... |
1058 |
raw_spin_lock_irqsave(&worker->lock, flags); |
9a6b06c8d kthread: allow to... |
1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 |
/* Do not bother with canceling when never queued. */ if (!work->worker) goto fast_queue; /* Work must not be used with >1 worker, see kthread_queue_work() */ WARN_ON_ONCE(work->worker != worker); /* Do not fight with another command that is canceling this work. */ if (work->canceling) goto out; ret = __kthread_cancel_work(work, true, &flags); fast_queue: __kthread_queue_delayed_work(worker, dwork, delay); out: |
fe99a4f4d kthread: Convert ... |
1075 |
raw_spin_unlock_irqrestore(&worker->lock, flags); |
9a6b06c8d kthread: allow to... |
1076 1077 1078 |
return ret; } EXPORT_SYMBOL_GPL(kthread_mod_delayed_work); |
37be45d49 kthread: allow to... |
1079 1080 1081 1082 1083 1084 1085 1086 |
static bool __kthread_cancel_work_sync(struct kthread_work *work, bool is_dwork) { struct kthread_worker *worker = work->worker; unsigned long flags; int ret = false; if (!worker) goto out; |
fe99a4f4d kthread: Convert ... |
1087 |
raw_spin_lock_irqsave(&worker->lock, flags); |
37be45d49 kthread: allow to... |
1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 |
/* Work must not be used with >1 worker, see kthread_queue_work(). */ WARN_ON_ONCE(work->worker != worker); ret = __kthread_cancel_work(work, is_dwork, &flags); if (worker->current_work != work) goto out_fast; /* * The work is in progress and we need to wait with the lock released. * In the meantime, block any queuing by setting the canceling counter. */ work->canceling++; |
fe99a4f4d kthread: Convert ... |
1101 |
raw_spin_unlock_irqrestore(&worker->lock, flags); |
37be45d49 kthread: allow to... |
1102 |
kthread_flush_work(work); |
fe99a4f4d kthread: Convert ... |
1103 |
raw_spin_lock_irqsave(&worker->lock, flags); |
37be45d49 kthread: allow to... |
1104 1105 1106 |
work->canceling--; out_fast: |
fe99a4f4d kthread: Convert ... |
1107 |
raw_spin_unlock_irqrestore(&worker->lock, flags); |
37be45d49 kthread: allow to... |
1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 |
out: return ret; } /** * kthread_cancel_work_sync - cancel a kthread work and wait for it to finish * @work: the kthread work to cancel * * Cancel @work and wait for its execution to finish. This function * can be used even if the work re-queues itself. On return from this * function, @work is guaranteed to be not pending or executing on any CPU. * * kthread_cancel_work_sync(&delayed_work->work) must not be used for * delayed_work's. Use kthread_cancel_delayed_work_sync() instead. * * The caller must ensure that the worker on which @work was last * queued can't be destroyed before this function returns. * * Return: %true if @work was pending, %false otherwise. */ bool kthread_cancel_work_sync(struct kthread_work *work) { return __kthread_cancel_work_sync(work, false); } EXPORT_SYMBOL_GPL(kthread_cancel_work_sync); /** * kthread_cancel_delayed_work_sync - cancel a kthread delayed work and * wait for it to finish. * @dwork: the kthread delayed work to cancel * * This is kthread_cancel_work_sync() for delayed works. * * Return: %true if @dwork was pending, %false otherwise. */ bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *dwork) { return __kthread_cancel_work_sync(&dwork->work, true); } EXPORT_SYMBOL_GPL(kthread_cancel_delayed_work_sync); |
b56c0d893 kthread: implemen... |
1148 |
/** |
3989144f8 kthread: kthread ... |
1149 |
* kthread_flush_worker - flush all current works on a kthread_worker |
b56c0d893 kthread: implemen... |
1150 1151 1152 1153 1154 |
* @worker: worker to flush * * Wait until all currently executing or pending works on @worker are * finished. */ |
3989144f8 kthread: kthread ... |
1155 |
void kthread_flush_worker(struct kthread_worker *worker) |
b56c0d893 kthread: implemen... |
1156 1157 1158 1159 1160 |
{ struct kthread_flush_work fwork = { KTHREAD_WORK_INIT(fwork.work, kthread_flush_work_fn), COMPLETION_INITIALIZER_ONSTACK(fwork.done), }; |
3989144f8 kthread: kthread ... |
1161 |
kthread_queue_work(worker, &fwork.work); |
b56c0d893 kthread: implemen... |
1162 1163 |
wait_for_completion(&fwork.done); } |
3989144f8 kthread: kthread ... |
1164 |
EXPORT_SYMBOL_GPL(kthread_flush_worker); |
35033fe9c kthread: add kthr... |
1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 |
/** * kthread_destroy_worker - destroy a kthread worker * @worker: worker to be destroyed * * Flush and destroy @worker. The simple flush is enough because the kthread * worker API is used only in trivial scenarios. There are no multi-step state * machines needed. */ void kthread_destroy_worker(struct kthread_worker *worker) { struct task_struct *task; task = worker->task; if (WARN_ON(!task)) return; kthread_flush_worker(worker); kthread_stop(task); WARN_ON(!list_empty(&worker->work_list)); kfree(worker); } EXPORT_SYMBOL(kthread_destroy_worker); |
05e3db95e kthread: add a me... |
1188 |
|
f5678e7f2 kernel: better do... |
1189 1190 1191 |
/** * kthread_use_mm - make the calling kthread operate on an address space * @mm: address space to operate on |
9bf5b9eb2 kernel: move use_... |
1192 |
*/ |
f5678e7f2 kernel: better do... |
1193 |
void kthread_use_mm(struct mm_struct *mm) |
9bf5b9eb2 kernel: move use_... |
1194 1195 1196 |
{ struct mm_struct *active_mm; struct task_struct *tsk = current; |
f5678e7f2 kernel: better do... |
1197 1198 |
WARN_ON_ONCE(!(tsk->flags & PF_KTHREAD)); WARN_ON_ONCE(tsk->mm); |
9bf5b9eb2 kernel: move use_... |
1199 |
task_lock(tsk); |
38cf307c1 mm: fix kthread_u... |
1200 1201 |
/* Hold off tlb flush IPIs while switching mm's */ local_irq_disable(); |
9bf5b9eb2 kernel: move use_... |
1202 1203 1204 1205 1206 1207 |
active_mm = tsk->active_mm; if (active_mm != mm) { mmgrab(mm); tsk->active_mm = mm; } tsk->mm = mm; |
38cf307c1 mm: fix kthread_u... |
1208 1209 |
switch_mm_irqs_off(active_mm, mm, tsk); local_irq_enable(); |
9bf5b9eb2 kernel: move use_... |
1210 1211 1212 1213 1214 1215 1216 |
task_unlock(tsk); #ifdef finish_arch_post_lock_switch finish_arch_post_lock_switch(); #endif if (active_mm != mm) mmdrop(active_mm); |
37c54f9bd kernel: set USER_... |
1217 |
|
3d13f313c uaccess: add forc... |
1218 |
to_kthread(tsk)->oldfs = force_uaccess_begin(); |
9bf5b9eb2 kernel: move use_... |
1219 |
} |
f5678e7f2 kernel: better do... |
1220 |
EXPORT_SYMBOL_GPL(kthread_use_mm); |
9bf5b9eb2 kernel: move use_... |
1221 |
|
f5678e7f2 kernel: better do... |
1222 1223 1224 |
/** * kthread_unuse_mm - reverse the effect of kthread_use_mm() * @mm: address space to operate on |
9bf5b9eb2 kernel: move use_... |
1225 |
*/ |
f5678e7f2 kernel: better do... |
1226 |
void kthread_unuse_mm(struct mm_struct *mm) |
9bf5b9eb2 kernel: move use_... |
1227 1228 |
{ struct task_struct *tsk = current; |
f5678e7f2 kernel: better do... |
1229 1230 |
WARN_ON_ONCE(!(tsk->flags & PF_KTHREAD)); WARN_ON_ONCE(!tsk->mm); |
3d13f313c uaccess: add forc... |
1231 |
force_uaccess_end(to_kthread(tsk)->oldfs); |
37c54f9bd kernel: set USER_... |
1232 |
|
9bf5b9eb2 kernel: move use_... |
1233 1234 |
task_lock(tsk); sync_mm_rss(mm); |
38cf307c1 mm: fix kthread_u... |
1235 |
local_irq_disable(); |
9bf5b9eb2 kernel: move use_... |
1236 1237 1238 |
tsk->mm = NULL; /* active_mm is still 'mm' */ enter_lazy_tlb(mm, tsk); |
38cf307c1 mm: fix kthread_u... |
1239 |
local_irq_enable(); |
9bf5b9eb2 kernel: move use_... |
1240 1241 |
task_unlock(tsk); } |
f5678e7f2 kernel: better do... |
1242 |
EXPORT_SYMBOL_GPL(kthread_unuse_mm); |
9bf5b9eb2 kernel: move use_... |
1243 |
|
0b508bc92 block: fix a buil... |
1244 |
#ifdef CONFIG_BLK_CGROUP |
05e3db95e kthread: add a me... |
1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 |
/** * kthread_associate_blkcg - associate blkcg to current kthread * @css: the cgroup info * * Current thread must be a kthread. The thread is running jobs on behalf of * other threads. In some cases, we expect the jobs attach cgroup info of * original threads instead of that of current thread. This function stores * original thread's cgroup info in current kthread context for later * retrieval. */ void kthread_associate_blkcg(struct cgroup_subsys_state *css) { struct kthread *kthread; if (!(current->flags & PF_KTHREAD)) return; kthread = to_kthread(current); if (!kthread) return; if (kthread->blkcg_css) { css_put(kthread->blkcg_css); kthread->blkcg_css = NULL; } if (css) { css_get(css); kthread->blkcg_css = css; } } EXPORT_SYMBOL(kthread_associate_blkcg); /** * kthread_blkcg - get associated blkcg css of current kthread * * Current thread must be a kthread. */ struct cgroup_subsys_state *kthread_blkcg(void) { struct kthread *kthread; if (current->flags & PF_KTHREAD) { kthread = to_kthread(current); if (kthread) return kthread->blkcg_css; } return NULL; } EXPORT_SYMBOL(kthread_blkcg); #endif |