diff options
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/async.c | 53 | ||||
-rw-r--r-- | kernel/workqueue.c | 84 |
2 files changed, 113 insertions, 24 deletions
diff --git a/kernel/async.c b/kernel/async.c index a893d6170944..f6bd0d9885e1 100644 --- a/kernel/async.c +++ b/kernel/async.c @@ -149,7 +149,25 @@ static void async_run_entry_fn(struct work_struct *work) wake_up(&async_done); } -static async_cookie_t __async_schedule(async_func_t func, void *data, struct async_domain *domain) +/** + * async_schedule_node_domain - NUMA specific version of async_schedule_domain + * @func: function to execute asynchronously + * @data: data pointer to pass to the function + * @node: NUMA node that we want to schedule this on or close to + * @domain: the domain + * + * Returns an async_cookie_t that may be used for checkpointing later. + * @domain may be used in the async_synchronize_*_domain() functions to + * wait within a certain synchronization domain rather than globally. + * + * Note: This function may be called from atomic or non-atomic contexts. + * + * The node requested will be honored on a best effort basis. If the node + * has no CPUs associated with it then the work is distributed among all + * available CPUs. + */ +async_cookie_t async_schedule_node_domain(async_func_t func, void *data, + int node, struct async_domain *domain) { struct async_entry *entry; unsigned long flags; @@ -195,43 +213,30 @@ static async_cookie_t __async_schedule(async_func_t func, void *data, struct asy current->flags |= PF_USED_ASYNC; /* schedule for execution */ - queue_work(system_unbound_wq, &entry->work); + queue_work_node(node, system_unbound_wq, &entry->work); return newcookie; } +EXPORT_SYMBOL_GPL(async_schedule_node_domain); /** - * async_schedule - schedule a function for asynchronous execution + * async_schedule_node - NUMA specific version of async_schedule * @func: function to execute asynchronously * @data: data pointer to pass to the function + * @node: NUMA node that we want to schedule this on or close to * * Returns an async_cookie_t that may be used for checkpointing later. * Note: This function may be called from atomic or non-atomic contexts. - */ -async_cookie_t async_schedule(async_func_t func, void *data) -{ - return __async_schedule(func, data, &async_dfl_domain); -} -EXPORT_SYMBOL_GPL(async_schedule); - -/** - * async_schedule_domain - schedule a function for asynchronous execution within a certain domain - * @func: function to execute asynchronously - * @data: data pointer to pass to the function - * @domain: the domain * - * Returns an async_cookie_t that may be used for checkpointing later. - * @domain may be used in the async_synchronize_*_domain() functions to - * wait within a certain synchronization domain rather than globally. A - * synchronization domain is specified via @domain. Note: This function - * may be called from atomic or non-atomic contexts. + * The node requested will be honored on a best effort basis. If the node + * has no CPUs associated with it then the work is distributed among all + * available CPUs. */ -async_cookie_t async_schedule_domain(async_func_t func, void *data, - struct async_domain *domain) +async_cookie_t async_schedule_node(async_func_t func, void *data, int node) { - return __async_schedule(func, data, domain); + return async_schedule_node_domain(func, data, node, &async_dfl_domain); } -EXPORT_SYMBOL_GPL(async_schedule_domain); +EXPORT_SYMBOL_GPL(async_schedule_node); /** * async_synchronize_full - synchronize all asynchronous function calls diff --git a/kernel/workqueue.c b/kernel/workqueue.c index fc5d23d752a5..1ce2697254d1 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1512,6 +1512,90 @@ bool queue_work_on(int cpu, struct workqueue_struct *wq, } EXPORT_SYMBOL(queue_work_on); +/** + * workqueue_select_cpu_near - Select a CPU based on NUMA node + * @node: NUMA node ID that we want to select a CPU from + * + * This function will attempt to find a "random" cpu available on a given + * node. If there are no CPUs available on the given node it will return + * WORK_CPU_UNBOUND indicating that we should just schedule to any + * available CPU if we need to schedule this work. + */ +static int workqueue_select_cpu_near(int node) +{ + int cpu; + + /* No point in doing this if NUMA isn't enabled for workqueues */ + if (!wq_numa_enabled) + return WORK_CPU_UNBOUND; + + /* Delay binding to CPU if node is not valid or online */ + if (node < 0 || node >= MAX_NUMNODES || !node_online(node)) + return WORK_CPU_UNBOUND; + + /* Use local node/cpu if we are already there */ + cpu = raw_smp_processor_id(); + if (node == cpu_to_node(cpu)) + return cpu; + + /* Use "random" otherwise know as "first" online CPU of node */ + cpu = cpumask_any_and(cpumask_of_node(node), cpu_online_mask); + + /* If CPU is valid return that, otherwise just defer */ + return cpu < nr_cpu_ids ? cpu : WORK_CPU_UNBOUND; +} + +/** + * queue_work_node - queue work on a "random" cpu for a given NUMA node + * @node: NUMA node that we are targeting the work for + * @wq: workqueue to use + * @work: work to queue + * + * We queue the work to a "random" CPU within a given NUMA node. The basic + * idea here is to provide a way to somehow associate work with a given + * NUMA node. + * + * This function will only make a best effort attempt at getting this onto + * the right NUMA node. If no node is requested or the requested node is + * offline then we just fall back to standard queue_work behavior. + * + * Currently the "random" CPU ends up being the first available CPU in the + * intersection of cpu_online_mask and the cpumask of the node, unless we + * are running on the node. In that case we just use the current CPU. + * + * Return: %false if @work was already on a queue, %true otherwise. + */ +bool queue_work_node(int node, struct workqueue_struct *wq, + struct work_struct *work) +{ + unsigned long flags; + bool ret = false; + + /* + * This current implementation is specific to unbound workqueues. + * Specifically we only return the first available CPU for a given + * node instead of cycling through individual CPUs within the node. + * + * If this is used with a per-cpu workqueue then the logic in + * workqueue_select_cpu_near would need to be updated to allow for + * some round robin type logic. + */ + WARN_ON_ONCE(!(wq->flags & WQ_UNBOUND)); + + local_irq_save(flags); + + if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) { + int cpu = workqueue_select_cpu_near(node); + + __queue_work(cpu, wq, work); + ret = true; + } + + local_irq_restore(flags); + return ret; +} +EXPORT_SYMBOL_GPL(queue_work_node); + void delayed_work_timer_fn(struct timer_list *t) { struct delayed_work *dwork = from_timer(dwork, t, timer); |