diff options
Diffstat (limited to 'kernel/padata.c')
-rw-r--r-- | kernel/padata.c | 386 |
1 files changed, 194 insertions, 192 deletions
diff --git a/kernel/padata.c b/kernel/padata.c index c3fec1413295..72777c10bb9c 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -2,7 +2,7 @@ /* * padata.c - generic interface to process data streams in parallel * - * See Documentation/padata.txt for an api documentation. + * See Documentation/core-api/padata.rst for more information. * * Copyright (C) 2008, 2009 secunet Security Networks AG * Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com> @@ -35,6 +35,8 @@ #define MAX_OBJ_NUM 1000 +static void padata_free_pd(struct parallel_data *pd); + static int padata_index_to_cpu(struct parallel_data *pd, int cpu_index) { int cpu, target_cpu; @@ -87,7 +89,7 @@ static void padata_parallel_worker(struct work_struct *parallel_work) /** * padata_do_parallel - padata parallelization function * - * @pinst: padata instance + * @ps: padatashell * @padata: object to be parallelized * @cb_cpu: pointer to the CPU that the serialization callback function should * run on. If it's not in the serial cpumask of @pinst @@ -97,17 +99,20 @@ static void padata_parallel_worker(struct work_struct *parallel_work) * The parallelization callback function will run with BHs off. * Note: Every object which is parallelized by padata_do_parallel * must be seen by padata_do_serial. + * + * Return: 0 on success or else negative error code. */ -int padata_do_parallel(struct padata_instance *pinst, +int padata_do_parallel(struct padata_shell *ps, struct padata_priv *padata, int *cb_cpu) { + struct padata_instance *pinst = ps->pinst; int i, cpu, cpu_index, target_cpu, err; struct padata_parallel_queue *queue; struct parallel_data *pd; rcu_read_lock_bh(); - pd = rcu_dereference_bh(pinst->pd); + pd = rcu_dereference_bh(ps->pd); err = -EINVAL; if (!(pinst->flags & PADATA_INIT) || pinst->flags & PADATA_INVALID) @@ -160,14 +165,12 @@ EXPORT_SYMBOL(padata_do_parallel); /* * padata_find_next - Find the next object that needs serialization. * - * Return values are: - * - * A pointer to the control struct of the next object that needs - * serialization, if present in one of the percpu reorder queues. - * - * NULL, if the next object that needs serialization will - * be parallel processed by another cpu and is not yet present in - * the cpu's reorder queue. + * Return: + * * A pointer to the control struct of the next object that needs + * serialization, if present in one of the percpu reorder queues. + * * NULL, if the next object that needs serialization will + * be parallel processed by another cpu and is not yet present in + * the cpu's reorder queue. */ static struct padata_priv *padata_find_next(struct parallel_data *pd, bool remove_object) @@ -199,7 +202,6 @@ static struct padata_priv *padata_find_next(struct parallel_data *pd, if (remove_object) { list_del_init(&padata->list); - atomic_dec(&pd->reorder_objects); ++pd->processed; pd->cpu = cpumask_next_wrap(cpu, pd->cpumask.pcpu, -1, false); } @@ -210,10 +212,10 @@ static struct padata_priv *padata_find_next(struct parallel_data *pd, static void padata_reorder(struct parallel_data *pd) { + struct padata_instance *pinst = pd->ps->pinst; int cb_cpu; struct padata_priv *padata; struct padata_serial_queue *squeue; - struct padata_instance *pinst = pd->pinst; struct padata_parallel_queue *next_queue; /* @@ -283,6 +285,7 @@ static void padata_serial_worker(struct work_struct *serial_work) struct padata_serial_queue *squeue; struct parallel_data *pd; LIST_HEAD(local_list); + int cnt; local_bh_disable(); squeue = container_of(serial_work, struct padata_serial_queue, work); @@ -292,6 +295,8 @@ static void padata_serial_worker(struct work_struct *serial_work) list_replace_init(&squeue->serial.list, &local_list); spin_unlock(&squeue->serial.lock); + cnt = 0; + while (!list_empty(&local_list)) { struct padata_priv *padata; @@ -301,9 +306,12 @@ static void padata_serial_worker(struct work_struct *serial_work) list_del_init(&padata->list); padata->serial(padata); - atomic_dec(&pd->refcnt); + cnt++; } local_bh_enable(); + + if (atomic_sub_and_test(cnt, &pd->refcnt)) + padata_free_pd(pd); } /** @@ -327,7 +335,6 @@ void padata_do_serial(struct padata_priv *padata) if (cur->seq_nr < padata->seq_nr) break; list_add(&padata->list, &cur->list); - atomic_inc(&pd->reorder_objects); spin_unlock(&pqueue->reorder.lock); /* @@ -341,36 +348,39 @@ void padata_do_serial(struct padata_priv *padata) } EXPORT_SYMBOL(padata_do_serial); -static int padata_setup_cpumasks(struct parallel_data *pd, - const struct cpumask *pcpumask, - const struct cpumask *cbcpumask) +static int padata_setup_cpumasks(struct padata_instance *pinst) { struct workqueue_attrs *attrs; + int err; + + attrs = alloc_workqueue_attrs(); + if (!attrs) + return -ENOMEM; + + /* Restrict parallel_wq workers to pd->cpumask.pcpu. */ + cpumask_copy(attrs->cpumask, pinst->cpumask.pcpu); + err = apply_workqueue_attrs(pinst->parallel_wq, attrs); + free_workqueue_attrs(attrs); + + return err; +} + +static int pd_setup_cpumasks(struct parallel_data *pd, + const struct cpumask *pcpumask, + const struct cpumask *cbcpumask) +{ int err = -ENOMEM; if (!alloc_cpumask_var(&pd->cpumask.pcpu, GFP_KERNEL)) goto out; - cpumask_and(pd->cpumask.pcpu, pcpumask, cpu_online_mask); - if (!alloc_cpumask_var(&pd->cpumask.cbcpu, GFP_KERNEL)) goto free_pcpu_mask; - cpumask_and(pd->cpumask.cbcpu, cbcpumask, cpu_online_mask); - attrs = alloc_workqueue_attrs(); - if (!attrs) - goto free_cbcpu_mask; - - /* Restrict parallel_wq workers to pd->cpumask.pcpu. */ - cpumask_copy(attrs->cpumask, pd->cpumask.pcpu); - err = apply_workqueue_attrs(pd->pinst->parallel_wq, attrs); - free_workqueue_attrs(attrs); - if (err < 0) - goto free_cbcpu_mask; + cpumask_copy(pd->cpumask.pcpu, pcpumask); + cpumask_copy(pd->cpumask.cbcpu, cbcpumask); return 0; -free_cbcpu_mask: - free_cpumask_var(pd->cpumask.cbcpu); free_pcpu_mask: free_cpumask_var(pd->cpumask.pcpu); out: @@ -414,12 +424,16 @@ static void padata_init_pqueues(struct parallel_data *pd) } /* Allocate and initialize the internal cpumask dependend resources. */ -static struct parallel_data *padata_alloc_pd(struct padata_instance *pinst, - const struct cpumask *pcpumask, - const struct cpumask *cbcpumask) +static struct parallel_data *padata_alloc_pd(struct padata_shell *ps) { + struct padata_instance *pinst = ps->pinst; + const struct cpumask *cbcpumask; + const struct cpumask *pcpumask; struct parallel_data *pd; + cbcpumask = pinst->rcpumask.cbcpu; + pcpumask = pinst->rcpumask.pcpu; + pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL); if (!pd) goto err; @@ -432,15 +446,14 @@ static struct parallel_data *padata_alloc_pd(struct padata_instance *pinst, if (!pd->squeue) goto err_free_pqueue; - pd->pinst = pinst; - if (padata_setup_cpumasks(pd, pcpumask, cbcpumask) < 0) + pd->ps = ps; + if (pd_setup_cpumasks(pd, pcpumask, cbcpumask)) goto err_free_squeue; padata_init_pqueues(pd); padata_init_squeues(pd); atomic_set(&pd->seq_nr, -1); - atomic_set(&pd->reorder_objects, 0); - atomic_set(&pd->refcnt, 0); + atomic_set(&pd->refcnt, 1); spin_lock_init(&pd->lock); pd->cpu = cpumask_first(pd->cpumask.pcpu); INIT_WORK(&pd->reorder_work, invoke_padata_reorder); @@ -466,29 +479,6 @@ static void padata_free_pd(struct parallel_data *pd) kfree(pd); } -/* Flush all objects out of the padata queues. */ -static void padata_flush_queues(struct parallel_data *pd) -{ - int cpu; - struct padata_parallel_queue *pqueue; - struct padata_serial_queue *squeue; - - for_each_cpu(cpu, pd->cpumask.pcpu) { - pqueue = per_cpu_ptr(pd->pqueue, cpu); - flush_work(&pqueue->work); - } - - if (atomic_read(&pd->reorder_objects)) - padata_reorder(pd); - - for_each_cpu(cpu, pd->cpumask.cbcpu) { - squeue = per_cpu_ptr(pd->squeue, cpu); - flush_work(&squeue->work); - } - - BUG_ON(atomic_read(&pd->refcnt) != 0); -} - static void __padata_start(struct padata_instance *pinst) { pinst->flags |= PADATA_INIT; @@ -502,72 +492,52 @@ static void __padata_stop(struct padata_instance *pinst) pinst->flags &= ~PADATA_INIT; synchronize_rcu(); - - get_online_cpus(); - padata_flush_queues(pinst->pd); - put_online_cpus(); } /* Replace the internal control structure with a new one. */ -static void padata_replace(struct padata_instance *pinst, - struct parallel_data *pd_new) +static int padata_replace_one(struct padata_shell *ps) +{ + struct parallel_data *pd_new; + + pd_new = padata_alloc_pd(ps); + if (!pd_new) + return -ENOMEM; + + ps->opd = rcu_dereference_protected(ps->pd, 1); + rcu_assign_pointer(ps->pd, pd_new); + + return 0; +} + +static int padata_replace(struct padata_instance *pinst) { - struct parallel_data *pd_old = pinst->pd; - int notification_mask = 0; + struct padata_shell *ps; + int err; pinst->flags |= PADATA_RESET; - rcu_assign_pointer(pinst->pd, pd_new); + cpumask_and(pinst->rcpumask.pcpu, pinst->cpumask.pcpu, + cpu_online_mask); - synchronize_rcu(); + cpumask_and(pinst->rcpumask.cbcpu, pinst->cpumask.cbcpu, + cpu_online_mask); - if (!cpumask_equal(pd_old->cpumask.pcpu, pd_new->cpumask.pcpu)) - notification_mask |= PADATA_CPU_PARALLEL; - if (!cpumask_equal(pd_old->cpumask.cbcpu, pd_new->cpumask.cbcpu)) - notification_mask |= PADATA_CPU_SERIAL; + list_for_each_entry(ps, &pinst->pslist, list) { + err = padata_replace_one(ps); + if (err) + break; + } - padata_flush_queues(pd_old); - padata_free_pd(pd_old); + synchronize_rcu(); - if (notification_mask) - blocking_notifier_call_chain(&pinst->cpumask_change_notifier, - notification_mask, - &pd_new->cpumask); + list_for_each_entry_continue_reverse(ps, &pinst->pslist, list) + if (atomic_dec_and_test(&ps->opd->refcnt)) + padata_free_pd(ps->opd); pinst->flags &= ~PADATA_RESET; -} - -/** - * padata_register_cpumask_notifier - Registers a notifier that will be called - * if either pcpu or cbcpu or both cpumasks change. - * - * @pinst: A poineter to padata instance - * @nblock: A pointer to notifier block. - */ -int padata_register_cpumask_notifier(struct padata_instance *pinst, - struct notifier_block *nblock) -{ - return blocking_notifier_chain_register(&pinst->cpumask_change_notifier, - nblock); -} -EXPORT_SYMBOL(padata_register_cpumask_notifier); -/** - * padata_unregister_cpumask_notifier - Unregisters cpumask notifier - * registered earlier using padata_register_cpumask_notifier - * - * @pinst: A pointer to data instance. - * @nlock: A pointer to notifier block. - */ -int padata_unregister_cpumask_notifier(struct padata_instance *pinst, - struct notifier_block *nblock) -{ - return blocking_notifier_chain_unregister( - &pinst->cpumask_change_notifier, - nblock); + return err; } -EXPORT_SYMBOL(padata_unregister_cpumask_notifier); - /* If cpumask contains no active cpu, we mark the instance as invalid. */ static bool padata_validate_cpumask(struct padata_instance *pinst, @@ -587,7 +557,7 @@ static int __padata_set_cpumasks(struct padata_instance *pinst, cpumask_var_t cbcpumask) { int valid; - struct parallel_data *pd; + int err; valid = padata_validate_cpumask(pinst, pcpumask); if (!valid) { @@ -600,29 +570,26 @@ static int __padata_set_cpumasks(struct padata_instance *pinst, __padata_stop(pinst); out_replace: - pd = padata_alloc_pd(pinst, pcpumask, cbcpumask); - if (!pd) - return -ENOMEM; - cpumask_copy(pinst->cpumask.pcpu, pcpumask); cpumask_copy(pinst->cpumask.cbcpu, cbcpumask); - padata_replace(pinst, pd); + err = padata_setup_cpumasks(pinst) ?: padata_replace(pinst); if (valid) __padata_start(pinst); - return 0; + return err; } /** - * padata_set_cpumask: Sets specified by @cpumask_type cpumask to the value - * equivalent to @cpumask. - * + * padata_set_cpumask - Sets specified by @cpumask_type cpumask to the value + * equivalent to @cpumask. * @pinst: padata instance * @cpumask_type: PADATA_CPU_SERIAL or PADATA_CPU_PARALLEL corresponding * to parallel and serial cpumasks respectively. * @cpumask: the cpumask to use + * + * Return: 0 on success or negative error code */ int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type, cpumask_var_t cpumask) @@ -630,8 +597,8 @@ int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type, struct cpumask *serial_mask, *parallel_mask; int err = -EINVAL; - mutex_lock(&pinst->lock); get_online_cpus(); + mutex_lock(&pinst->lock); switch (cpumask_type) { case PADATA_CPU_PARALLEL: @@ -649,8 +616,8 @@ int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type, err = __padata_set_cpumasks(pinst, parallel_mask, serial_mask); out: - put_online_cpus(); mutex_unlock(&pinst->lock); + put_online_cpus(); return err; } @@ -660,6 +627,8 @@ EXPORT_SYMBOL(padata_set_cpumask); * padata_start - start the parallel processing * * @pinst: padata instance to start + * + * Return: 0 on success or negative error code */ int padata_start(struct padata_instance *pinst) { @@ -695,82 +664,33 @@ EXPORT_SYMBOL(padata_stop); static int __padata_add_cpu(struct padata_instance *pinst, int cpu) { - struct parallel_data *pd; + int err = 0; if (cpumask_test_cpu(cpu, cpu_online_mask)) { - pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu, - pinst->cpumask.cbcpu); - if (!pd) - return -ENOMEM; - - padata_replace(pinst, pd); + err = padata_replace(pinst); if (padata_validate_cpumask(pinst, pinst->cpumask.pcpu) && padata_validate_cpumask(pinst, pinst->cpumask.cbcpu)) __padata_start(pinst); } - return 0; + return err; } static int __padata_remove_cpu(struct padata_instance *pinst, int cpu) { - struct parallel_data *pd = NULL; - - if (cpumask_test_cpu(cpu, cpu_online_mask)) { + int err = 0; + if (!cpumask_test_cpu(cpu, cpu_online_mask)) { if (!padata_validate_cpumask(pinst, pinst->cpumask.pcpu) || !padata_validate_cpumask(pinst, pinst->cpumask.cbcpu)) __padata_stop(pinst); - pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu, - pinst->cpumask.cbcpu); - if (!pd) - return -ENOMEM; - - padata_replace(pinst, pd); - - cpumask_clear_cpu(cpu, pd->cpumask.cbcpu); - cpumask_clear_cpu(cpu, pd->cpumask.pcpu); + err = padata_replace(pinst); } - return 0; -} - - /** - * padata_remove_cpu - remove a cpu from the one or both(serial and parallel) - * padata cpumasks. - * - * @pinst: padata instance - * @cpu: cpu to remove - * @mask: bitmask specifying from which cpumask @cpu should be removed - * The @mask may be any combination of the following flags: - * PADATA_CPU_SERIAL - serial cpumask - * PADATA_CPU_PARALLEL - parallel cpumask - */ -int padata_remove_cpu(struct padata_instance *pinst, int cpu, int mask) -{ - int err; - - if (!(mask & (PADATA_CPU_SERIAL | PADATA_CPU_PARALLEL))) - return -EINVAL; - - mutex_lock(&pinst->lock); - - get_online_cpus(); - if (mask & PADATA_CPU_SERIAL) - cpumask_clear_cpu(cpu, pinst->cpumask.cbcpu); - if (mask & PADATA_CPU_PARALLEL) - cpumask_clear_cpu(cpu, pinst->cpumask.pcpu); - - err = __padata_remove_cpu(pinst, cpu); - put_online_cpus(); - - mutex_unlock(&pinst->lock); - return err; } -EXPORT_SYMBOL(padata_remove_cpu); static inline int pinst_has_cpu(struct padata_instance *pinst, int cpu) { @@ -793,7 +713,7 @@ static int padata_cpu_online(unsigned int cpu, struct hlist_node *node) return ret; } -static int padata_cpu_prep_down(unsigned int cpu, struct hlist_node *node) +static int padata_cpu_dead(unsigned int cpu, struct hlist_node *node) { struct padata_instance *pinst; int ret; @@ -814,11 +734,15 @@ static enum cpuhp_state hp_online; static void __padata_free(struct padata_instance *pinst) { #ifdef CONFIG_HOTPLUG_CPU + cpuhp_state_remove_instance_nocalls(CPUHP_PADATA_DEAD, &pinst->node); cpuhp_state_remove_instance_nocalls(hp_online, &pinst->node); #endif + WARN_ON(!list_empty(&pinst->pslist)); + padata_stop(pinst); - padata_free_pd(pinst->pd); + free_cpumask_var(pinst->rcpumask.cbcpu); + free_cpumask_var(pinst->rcpumask.pcpu); free_cpumask_var(pinst->cpumask.pcpu); free_cpumask_var(pinst->cpumask.cbcpu); destroy_workqueue(pinst->serial_wq); @@ -959,13 +883,14 @@ static struct kobj_type padata_attr_type = { * @name: used to identify the instance * @pcpumask: cpumask that will be used for padata parallelization * @cbcpumask: cpumask that will be used for padata serialization + * + * Return: new instance on success, NULL on error */ static struct padata_instance *padata_alloc(const char *name, const struct cpumask *pcpumask, const struct cpumask *cbcpumask) { struct padata_instance *pinst; - struct parallel_data *pd = NULL; pinst = kzalloc(sizeof(struct padata_instance), GFP_KERNEL); if (!pinst) @@ -993,29 +918,40 @@ static struct padata_instance *padata_alloc(const char *name, !padata_validate_cpumask(pinst, cbcpumask)) goto err_free_masks; - pd = padata_alloc_pd(pinst, pcpumask, cbcpumask); - if (!pd) + if (!alloc_cpumask_var(&pinst->rcpumask.pcpu, GFP_KERNEL)) goto err_free_masks; + if (!alloc_cpumask_var(&pinst->rcpumask.cbcpu, GFP_KERNEL)) + goto err_free_rcpumask_pcpu; - rcu_assign_pointer(pinst->pd, pd); + INIT_LIST_HEAD(&pinst->pslist); cpumask_copy(pinst->cpumask.pcpu, pcpumask); cpumask_copy(pinst->cpumask.cbcpu, cbcpumask); + cpumask_and(pinst->rcpumask.pcpu, pcpumask, cpu_online_mask); + cpumask_and(pinst->rcpumask.cbcpu, cbcpumask, cpu_online_mask); + + if (padata_setup_cpumasks(pinst)) + goto err_free_rcpumask_cbcpu; pinst->flags = 0; - BLOCKING_INIT_NOTIFIER_HEAD(&pinst->cpumask_change_notifier); kobject_init(&pinst->kobj, &padata_attr_type); mutex_init(&pinst->lock); #ifdef CONFIG_HOTPLUG_CPU cpuhp_state_add_instance_nocalls_cpuslocked(hp_online, &pinst->node); + cpuhp_state_add_instance_nocalls_cpuslocked(CPUHP_PADATA_DEAD, + &pinst->node); #endif put_online_cpus(); return pinst; +err_free_rcpumask_cbcpu: + free_cpumask_var(pinst->rcpumask.cbcpu); +err_free_rcpumask_pcpu: + free_cpumask_var(pinst->rcpumask.pcpu); err_free_masks: free_cpumask_var(pinst->cpumask.pcpu); free_cpumask_var(pinst->cpumask.cbcpu); @@ -1036,6 +972,8 @@ err: * parallel workers. * * @name: used to identify the instance + * + * Return: new instance on success, NULL on error */ struct padata_instance *padata_alloc_possible(const char *name) { @@ -1046,7 +984,7 @@ EXPORT_SYMBOL(padata_alloc_possible); /** * padata_free - free a padata instance * - * @padata_inst: padata instance to free + * @pinst: padata instance to free */ void padata_free(struct padata_instance *pinst) { @@ -1054,6 +992,63 @@ void padata_free(struct padata_instance *pinst) } EXPORT_SYMBOL(padata_free); +/** + * padata_alloc_shell - Allocate and initialize padata shell. + * + * @pinst: Parent padata_instance object. + * + * Return: new shell on success, NULL on error + */ +struct padata_shell *padata_alloc_shell(struct padata_instance *pinst) +{ + struct parallel_data *pd; + struct padata_shell *ps; + + ps = kzalloc(sizeof(*ps), GFP_KERNEL); + if (!ps) + goto out; + + ps->pinst = pinst; + + get_online_cpus(); + pd = padata_alloc_pd(ps); + put_online_cpus(); + + if (!pd) + goto out_free_ps; + + mutex_lock(&pinst->lock); + RCU_INIT_POINTER(ps->pd, pd); + list_add(&ps->list, &pinst->pslist); + mutex_unlock(&pinst->lock); + + return ps; + +out_free_ps: + kfree(ps); +out: + return NULL; +} +EXPORT_SYMBOL(padata_alloc_shell); + +/** + * padata_free_shell - free a padata shell + * + * @ps: padata shell to free + */ +void padata_free_shell(struct padata_shell *ps) +{ + struct padata_instance *pinst = ps->pinst; + + mutex_lock(&pinst->lock); + list_del(&ps->list); + padata_free_pd(rcu_dereference_protected(ps->pd, 1)); + mutex_unlock(&pinst->lock); + + kfree(ps); +} +EXPORT_SYMBOL(padata_free_shell); + #ifdef CONFIG_HOTPLUG_CPU static __init int padata_driver_init(void) @@ -1061,17 +1056,24 @@ static __init int padata_driver_init(void) int ret; ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "padata:online", - padata_cpu_online, - padata_cpu_prep_down); + padata_cpu_online, NULL); if (ret < 0) return ret; hp_online = ret; + + ret = cpuhp_setup_state_multi(CPUHP_PADATA_DEAD, "padata:dead", + NULL, padata_cpu_dead); + if (ret < 0) { + cpuhp_remove_multi_state(hp_online); + return ret; + } return 0; } module_init(padata_driver_init); static __exit void padata_driver_exit(void) { + cpuhp_remove_multi_state(CPUHP_PADATA_DEAD); cpuhp_remove_multi_state(hp_online); } module_exit(padata_driver_exit); |