Get rid of the hotplug notifiers and use the generic hotplug thread infrastructure. Signed-off-by: Thomas Gleixner --- drivers/infiniband/hw/ehca/ehca_irq.c | 240 ++++++++++++---------------------- drivers/infiniband/hw/ehca/ehca_irq.h | 5 2 files changed, 92 insertions(+), 153 deletions(-) Index: tip/drivers/infiniband/hw/ehca/ehca_irq.c =================================================================== --- tip.orig/drivers/infiniband/hw/ehca/ehca_irq.c +++ tip/drivers/infiniband/hw/ehca/ehca_irq.c @@ -42,6 +42,7 @@ */ #include +#include #include "ehca_classes.h" #include "ehca_irq.h" @@ -652,7 +653,7 @@ void ehca_tasklet_eq(unsigned long data) ehca_process_eq((struct ehca_shca*)data, 1); } -static inline int find_next_online_cpu(struct ehca_comp_pool *pool) +static int find_next_online_cpu(struct ehca_comp_pool *pool) { int cpu; unsigned long flags; @@ -662,10 +663,15 @@ static inline int find_next_online_cpu(s ehca_dmp(cpu_online_mask, cpumask_size(), ""); spin_lock_irqsave(&pool->last_cpu_lock, flags); - cpu = cpumask_next(pool->last_cpu, cpu_online_mask); - if (cpu >= nr_cpu_ids) - cpu = cpumask_first(cpu_online_mask); - pool->last_cpu = cpu; + while (1) { + cpu = cpumask_next(pool->last_cpu, cpu_online_mask); + if (cpu >= nr_cpu_ids) + cpu = cpumask_first(cpu_online_mask); + pool->last_cpu = cpu; + /* Might be on the way out */ + if (per_cpu_ptr(pool->cpu_comp_tasks, cpu)->active) + break; + } spin_unlock_irqrestore(&pool->last_cpu_lock, flags); return cpu; @@ -719,19 +725,18 @@ static void queue_comp_task(struct ehca_ static void run_comp_task(struct ehca_cpu_comp_task *cct) { struct ehca_cq *cq; - unsigned long flags; - spin_lock_irqsave(&cct->task_lock, flags); + spin_lock_irq(&cct->task_lock); while (!list_empty(&cct->cq_list)) { cq = list_entry(cct->cq_list.next, struct ehca_cq, entry); - spin_unlock_irqrestore(&cct->task_lock, flags); + spin_unlock_irq(&cct->task_lock); comp_event_callback(cq); if (atomic_dec_and_test(&cq->nr_events)) wake_up(&cq->wait_completion); - spin_lock_irqsave(&cct->task_lock, flags); + spin_lock_irq(&cct->task_lock); spin_lock(&cq->task_lock); cq->nr_callbacks--; if (!cq->nr_callbacks) { @@ -741,17 +746,51 @@ static void run_comp_task(struct ehca_cp spin_unlock(&cq->task_lock); } - spin_unlock_irqrestore(&cct->task_lock, flags); + spin_unlock_irq(&cct->task_lock); } -static int comp_task(void *__cct) +static void comp_task_park(unsigned int cpu) { - struct ehca_cpu_comp_task *cct = __cct; - int cql_empty; + struct ehca_cpu_comp_task *cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu); + struct ehca_cpu_comp_task *target; + struct ehca_cq *cq, *tmp; + LIST_HEAD(list); + + spin_lock_irq(&cct->task_lock); + cct->cq_jobs = 0; + cct->active = 0; + list_splice_init(&cct->cq_list, &list); + spin_unlock_irq(&cct->task_lock); + + cpu = find_next_online_cpu(pool); + target = per_cpu_ptr(pool->cpu_comp_tasks, cpu); + spin_lock_irq(&target->task_lock); + list_for_each_entry_safe(cq, tmp, &list, entry) { + list_del(&cq->entry); + __queue_comp_task(cq, target); + } + spin_unlock_irq(&target->task_lock); +} + +static void comp_task_stop(unsigned int cpu, bool online) +{ + struct ehca_cpu_comp_task *cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu); + + spin_lock_irq(&cct->task_lock); + cct->cq_jobs = 0; + cct->active = 0; + WARN_ON(!list_empty(&cct->cq_list)); + spin_unlock_irq(&cct->task_lock); +} + +static int comp_task(void *td) +{ + struct ehca_cpu_comp_task *cct = this_cpu_ptr(pool->cpu_comp_tasks); DECLARE_WAITQUEUE(wait, current); + int cql_empty; - set_current_state(TASK_INTERRUPTIBLE); - while (!kthread_should_stop()) { + while (!smpboot_thread_check_parking(td)) { + set_current_state(TASK_INTERRUPTIBLE); add_wait_queue(&cct->wait_queue, &wait); spin_lock_irq(&cct->task_lock); @@ -768,131 +807,21 @@ static int comp_task(void *__cct) cql_empty = list_empty(&cct->cq_list); spin_unlock_irq(&cct->task_lock); if (!cql_empty) - run_comp_task(__cct); - - set_current_state(TASK_INTERRUPTIBLE); + run_comp_task(cct); } - __set_current_state(TASK_RUNNING); - return 0; } -static struct task_struct *create_comp_task(struct ehca_comp_pool *pool, - int cpu) -{ - struct ehca_cpu_comp_task *cct; - - cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu); - spin_lock_init(&cct->task_lock); - INIT_LIST_HEAD(&cct->cq_list); - init_waitqueue_head(&cct->wait_queue); - cct->task = kthread_create_on_node(comp_task, cct, cpu_to_node(cpu), - "ehca_comp/%d", cpu); - - return cct->task; -} - -static void destroy_comp_task(struct ehca_comp_pool *pool, - int cpu) -{ - struct ehca_cpu_comp_task *cct; - struct task_struct *task; - unsigned long flags_cct; - - cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu); - - spin_lock_irqsave(&cct->task_lock, flags_cct); - - task = cct->task; - cct->task = NULL; - cct->cq_jobs = 0; - - spin_unlock_irqrestore(&cct->task_lock, flags_cct); - - if (task) - kthread_stop(task); -} - -static void __cpuinit take_over_work(struct ehca_comp_pool *pool, int cpu) -{ - struct ehca_cpu_comp_task *cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu); - LIST_HEAD(list); - struct ehca_cq *cq; - unsigned long flags_cct; - - spin_lock_irqsave(&cct->task_lock, flags_cct); - - list_splice_init(&cct->cq_list, &list); - - while (!list_empty(&list)) { - cq = list_entry(cct->cq_list.next, struct ehca_cq, entry); - - list_del(&cq->entry); - __queue_comp_task(cq, this_cpu_ptr(pool->cpu_comp_tasks)); - } - - spin_unlock_irqrestore(&cct->task_lock, flags_cct); - -} - -static int __cpuinit comp_pool_callback(struct notifier_block *nfb, - unsigned long action, - void *hcpu) -{ - unsigned int cpu = (unsigned long)hcpu; - struct ehca_cpu_comp_task *cct; - - switch (action) { - case CPU_UP_PREPARE: - case CPU_UP_PREPARE_FROZEN: - ehca_gen_dbg("CPU: %x (CPU_PREPARE)", cpu); - if (!create_comp_task(pool, cpu)) { - ehca_gen_err("Can't create comp_task for cpu: %x", cpu); - return notifier_from_errno(-ENOMEM); - } - break; - case CPU_UP_CANCELED: - case CPU_UP_CANCELED_FROZEN: - ehca_gen_dbg("CPU: %x (CPU_CANCELED)", cpu); - cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu); - kthread_bind(cct->task, cpumask_any(cpu_online_mask)); - destroy_comp_task(pool, cpu); - break; - case CPU_ONLINE: - case CPU_ONLINE_FROZEN: - ehca_gen_dbg("CPU: %x (CPU_ONLINE)", cpu); - cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu); - kthread_bind(cct->task, cpu); - wake_up_process(cct->task); - break; - case CPU_DOWN_PREPARE: - case CPU_DOWN_PREPARE_FROZEN: - ehca_gen_dbg("CPU: %x (CPU_DOWN_PREPARE)", cpu); - break; - case CPU_DOWN_FAILED: - case CPU_DOWN_FAILED_FROZEN: - ehca_gen_dbg("CPU: %x (CPU_DOWN_FAILED)", cpu); - break; - case CPU_DEAD: - case CPU_DEAD_FROZEN: - ehca_gen_dbg("CPU: %x (CPU_DEAD)", cpu); - destroy_comp_task(pool, cpu); - take_over_work(pool, cpu); - break; - } - - return NOTIFY_OK; -} - -static struct notifier_block comp_pool_callback_nb __cpuinitdata = { - .notifier_call = comp_pool_callback, - .priority = 0, +static struct smp_hotplug_thread comp_pool_threads = { + .thread_fn = comp_task, + .thread_comm = "ehca_comp/%u", + .cleanup = comp_task_stop, + .park = comp_task_park, }; int ehca_create_comp_pool(void) { - int cpu; - struct task_struct *task; + int cpu, ret = -ENOMEM; if (!ehca_scaling_code) return 0; @@ -905,38 +834,47 @@ int ehca_create_comp_pool(void) pool->last_cpu = cpumask_any(cpu_online_mask); pool->cpu_comp_tasks = alloc_percpu(struct ehca_cpu_comp_task); - if (pool->cpu_comp_tasks == NULL) { - kfree(pool); - return -EINVAL; - } + if (!pool->cpu_comp_tasks) + goto out_pool; - for_each_online_cpu(cpu) { - task = create_comp_task(pool, cpu); - if (task) { - kthread_bind(task, cpu); - wake_up_process(task); - } + pool->cpu_comp_threads = alloc_percpu(struct task_struct *); + if (!pool->cpu_comp_threads) + goto out_tasks; + + for_each_present_cpu(cpu) { + struct ehca_cpu_comp_task *cct; + + cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu); + spin_lock_init(&cct->task_lock); + INIT_LIST_HEAD(&cct->cq_list); + init_waitqueue_head(&cct->wait_queue); } - register_hotcpu_notifier(&comp_pool_callback_nb); + comp_pool_threads.store = pool->cpu_comp_threads; + ret = smpboot_register_percpu_thread(&comp_pool_threads); + if (ret) + goto out_threads; - printk(KERN_INFO "eHCA scaling code enabled\n"); + pr_info("eHCA scaling code enabled\n"); + return ret; - return 0; +out_threads: + free_percpu(pool->cpu_comp_threads); +out_tasks: + free_percpu(pool->cpu_comp_tasks); +out_pool: + kfree(pool); + return ret; } void ehca_destroy_comp_pool(void) { - int i; - if (!ehca_scaling_code) return; - unregister_hotcpu_notifier(&comp_pool_callback_nb); - - for_each_online_cpu(i) - destroy_comp_task(pool, i); + smpboot_unregister_percpu_thread(&comp_pool_threads); + free_percpu(pool->cpu_comp_threads); free_percpu(pool->cpu_comp_tasks); kfree(pool); } Index: tip/drivers/infiniband/hw/ehca/ehca_irq.h =================================================================== --- tip.orig/drivers/infiniband/hw/ehca/ehca_irq.h +++ tip/drivers/infiniband/hw/ehca/ehca_irq.h @@ -60,13 +60,14 @@ void ehca_process_eq(struct ehca_shca *s struct ehca_cpu_comp_task { wait_queue_head_t wait_queue; struct list_head cq_list; - struct task_struct *task; spinlock_t task_lock; int cq_jobs; + int active; }; struct ehca_comp_pool { - struct ehca_cpu_comp_task *cpu_comp_tasks; + struct ehca_cpu_comp_task __percpu *cpu_comp_tasks; + struct task_struct * __percpu *cpu_comp_threads; int last_cpu; 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