From: Rusty Russell This simply changes over the migration threads, the workqueue threads and the ksoftirqd threads to use kthread. --- kernel/sched.c | 60 +++++++++++++++-------------------------------------- kernel/softirq.c | 22 ++++++++----------- kernel/workqueue.c | 60 ++++++++++++++++++----------------------------------- 3 files changed, 49 insertions(+), 93 deletions(-) diff -puN kernel/sched.c~use-kthread-primitives kernel/sched.c --- 25/kernel/sched.c~use-kthread-primitives 2004-02-06 18:50:13.000000000 -0800 +++ 25-akpm/kernel/sched.c 2004-02-06 18:50:14.000000000 -0800 @@ -37,6 +37,7 @@ #include #include #include +#include #ifdef CONFIG_NUMA #define cpu_to_node_mask(cpu) node_to_cpumask(cpu_to_node(cpu)) @@ -3072,12 +3073,6 @@ out: local_irq_restore(flags); } -typedef struct { - int cpu; - struct completion startup_done; - task_t *task; -} migration_startup_t; - /* * migration_thread - this is a highprio system thread that performs * thread migration by bumping thread off CPU then 'pushing' onto @@ -3087,27 +3082,17 @@ static int migration_thread(void * data) { /* Marking "param" __user is ok, since we do a set_fs(KERNEL_DS); */ struct sched_param __user param = { .sched_priority = MAX_RT_PRIO-1 }; - migration_startup_t *startup = data; - int cpu = startup->cpu; runqueue_t *rq; + int cpu = (long)data; int ret; - startup->task = current; - complete(&startup->startup_done); - set_current_state(TASK_UNINTERRUPTIBLE); - schedule(); - BUG_ON(smp_processor_id() != cpu); - - daemonize("migration/%d", cpu); - set_fs(KERNEL_DS); - ret = setscheduler(0, SCHED_FIFO, ¶m); rq = this_rq(); - rq->migration_thread = current; + BUG_ON(rq->migration_thread != current); - for (;;) { + while (!signal_pending(current)) { struct list_head *head; migration_req_t *req; @@ -3135,6 +3120,7 @@ static int migration_thread(void * data) __migrate_task(req->task, req->dest_cpu); complete(&req->done); } + return 0; } /* @@ -3144,37 +3130,27 @@ static int migration_thread(void * data) static int migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) { - long cpu = (long)hcpu; - migration_startup_t startup; + int cpu = (long)hcpu; + struct task_struct *p; switch (action) { case CPU_ONLINE: - - printk("Starting migration thread for cpu %li\n", cpu); - - startup.cpu = cpu; - startup.task = NULL; - init_completion(&startup.startup_done); - - kernel_thread(migration_thread, &startup, CLONE_KERNEL); - wait_for_completion(&startup.startup_done); - wait_task_inactive(startup.task); - - startup.task->thread_info->cpu = cpu; - startup.task->cpus_allowed = cpumask_of_cpu(cpu); - - wake_up_process(startup.task); - - while (!cpu_rq(cpu)->migration_thread) - yield(); - + p = kthread_create(migration_thread, hcpu, "migration/%d",cpu); + if (IS_ERR(p)) + return NOTIFY_BAD; + kthread_bind(p, cpu); + cpu_rq(cpu)->migration_thread = p; + wake_up_process(p); break; } return NOTIFY_OK; } -static struct notifier_block migration_notifier - = { .notifier_call = &migration_call }; +/* Want this before the other threads, so they can use set_cpus_allowed. */ +static struct notifier_block migration_notifier = { + .notifier_call = &migration_call, + .priority = 10, +}; int __init migration_init(void) { diff -puN kernel/softirq.c~use-kthread-primitives kernel/softirq.c --- 25/kernel/softirq.c~use-kthread-primitives 2004-02-06 18:50:13.000000000 -0800 +++ 25-akpm/kernel/softirq.c 2004-02-06 18:50:14.000000000 -0800 @@ -14,6 +14,7 @@ #include #include #include +#include /* - No shared variables, all the data are CPU local. @@ -348,20 +349,14 @@ static int ksoftirqd(void * __bind_cpu) { int cpu = (int) (long) __bind_cpu; - daemonize("ksoftirqd/%d", cpu); set_user_nice(current, 19); current->flags |= PF_IOTHREAD; - /* Migrate to the right CPU */ - set_cpus_allowed(current, cpumask_of_cpu(cpu)); BUG_ON(smp_processor_id() != cpu); - __set_current_state(TASK_INTERRUPTIBLE); - mb(); + set_current_state(TASK_INTERRUPTIBLE); - __get_cpu_var(ksoftirqd) = current; - - for (;;) { + while (!signal_pending(current)) { if (!local_softirq_pending()) schedule(); @@ -374,6 +369,7 @@ static int ksoftirqd(void * __bind_cpu) __set_current_state(TASK_INTERRUPTIBLE); } + return 0; } static int __devinit cpu_callback(struct notifier_block *nfb, @@ -381,15 +377,17 @@ static int __devinit cpu_callback(struct void *hcpu) { int hotcpu = (unsigned long)hcpu; + struct task_struct *p; if (action == CPU_ONLINE) { - if (kernel_thread(ksoftirqd, hcpu, CLONE_KERNEL) < 0) { + p = kthread_create(ksoftirqd, hcpu, "ksoftirqd/%d", hotcpu); + if (IS_ERR(p)) { printk("ksoftirqd for %i failed\n", hotcpu); return NOTIFY_BAD; } - - while (!per_cpu(ksoftirqd, hotcpu)) - yield(); + per_cpu(ksoftirqd, hotcpu) = p; + kthread_bind(p, hotcpu); + wake_up_process(p); } return NOTIFY_OK; } diff -puN kernel/workqueue.c~use-kthread-primitives kernel/workqueue.c --- 25/kernel/workqueue.c~use-kthread-primitives 2004-02-06 18:50:13.000000000 -0800 +++ 25-akpm/kernel/workqueue.c 2004-02-06 18:50:14.000000000 -0800 @@ -22,6 +22,7 @@ #include #include #include +#include /* * The per-CPU workqueue. @@ -45,7 +46,6 @@ struct cpu_workqueue_struct { struct workqueue_struct *wq; task_t *thread; - struct completion exit; } ____cacheline_aligned; @@ -153,28 +153,23 @@ static inline void run_workqueue(struct spin_unlock_irqrestore(&cwq->lock, flags); } -typedef struct startup_s { - struct cpu_workqueue_struct *cwq; - struct completion done; - const char *name; -} startup_t; - -static int worker_thread(void *__startup) +static int worker_thread(void *__cwq) { - startup_t *startup = __startup; - struct cpu_workqueue_struct *cwq = startup->cwq; + struct cpu_workqueue_struct *cwq = __cwq; int cpu = cwq - cwq->wq->cpu_wq; DECLARE_WAITQUEUE(wait, current); struct k_sigaction sa; + sigset_t blocked; - daemonize("%s/%d", startup->name, cpu); current->flags |= PF_IOTHREAD; - cwq->thread = current; set_user_nice(current, -10); - set_cpus_allowed(current, cpumask_of_cpu(cpu)); + BUG_ON(smp_processor_id() != cpu); - complete(&startup->done); + /* Block and flush all signals */ + sigfillset(&blocked); + sigprocmask(SIG_BLOCK, &blocked, NULL); + flush_signals(current); /* SIG_IGN makes children autoreap: see do_notify_parent(). */ sa.sa.sa_handler = SIG_IGN; @@ -182,12 +177,10 @@ static int worker_thread(void *__startup siginitset(&sa.sa.sa_mask, sigmask(SIGCHLD)); do_sigaction(SIGCHLD, &sa, (struct k_sigaction *)0); - for (;;) { + while (!signal_pending(current)) { set_task_state(current, TASK_INTERRUPTIBLE); add_wait_queue(&cwq->more_work, &wait); - if (!cwq->thread) - break; if (list_empty(&cwq->worklist)) schedule(); else @@ -197,9 +190,6 @@ static int worker_thread(void *__startup if (!list_empty(&cwq->worklist)) run_workqueue(cwq); } - remove_wait_queue(&cwq->more_work, &wait); - complete(&cwq->exit); - return 0; } @@ -251,9 +241,8 @@ static int create_workqueue_thread(struc const char *name, int cpu) { - startup_t startup; struct cpu_workqueue_struct *cwq = wq->cpu_wq + cpu; - int ret; + struct task_struct *p; spin_lock_init(&cwq->lock); cwq->wq = wq; @@ -263,17 +252,13 @@ static int create_workqueue_thread(struc INIT_LIST_HEAD(&cwq->worklist); init_waitqueue_head(&cwq->more_work); init_waitqueue_head(&cwq->work_done); - init_completion(&cwq->exit); - init_completion(&startup.done); - startup.cwq = cwq; - startup.name = name; - ret = kernel_thread(worker_thread, &startup, CLONE_FS | CLONE_FILES); - if (ret >= 0) { - wait_for_completion(&startup.done); - BUG_ON(!cwq->thread); - } - return ret; + p = kthread_create(worker_thread, cwq, "%s/%d", name, cpu); + if (IS_ERR(p)) + return PTR_ERR(p); + cwq->thread = p; + kthread_bind(p, cpu); + return 0; } struct workqueue_struct *create_workqueue(const char *name) @@ -292,6 +277,8 @@ struct workqueue_struct *create_workqueu continue; if (create_workqueue_thread(wq, name, cpu) < 0) destroy = 1; + else + wake_up_process(wq->cpu_wq[cpu].thread); } /* * Was there any error during startup? If yes then clean up: @@ -308,13 +295,8 @@ static void cleanup_workqueue_thread(str struct cpu_workqueue_struct *cwq; cwq = wq->cpu_wq + cpu; - if (cwq->thread) { - /* Tell thread to exit and wait for it. */ - cwq->thread = NULL; - wake_up(&cwq->more_work); - - wait_for_completion(&cwq->exit); - } + if (cwq->thread) + kthread_stop(cwq->thread); } void destroy_workqueue(struct workqueue_struct *wq) _