#include <linux/mutex.h>
#include <linux/sched.h>
#include <linux/slab.h>
+#include <linux/sysfs.h>
#include <linux/rcupdate.h>
-#define MAX_SEQ_NR INT_MAX - NR_CPUS
+#define MAX_SEQ_NR (INT_MAX - NR_CPUS)
#define MAX_OBJ_NUM 1000
static int padata_index_to_cpu(struct parallel_data *pd, int cpu_index)
{
int cpu, target_cpu;
- target_cpu = cpumask_first(pd->cpumask);
+ target_cpu = cpumask_first(pd->cpumask.pcpu);
for (cpu = 0; cpu < cpu_index; cpu++)
- target_cpu = cpumask_next(target_cpu, pd->cpumask);
+ target_cpu = cpumask_next(target_cpu, pd->cpumask.pcpu);
return target_cpu;
}
* Hash the sequence numbers to the cpus by taking
* seq_nr mod. number of cpus in use.
*/
- cpu_index = padata->seq_nr % cpumask_weight(pd->cpumask);
+ cpu_index = padata->seq_nr % cpumask_weight(pd->cpumask.pcpu);
return padata_index_to_cpu(pd, cpu_index);
}
-static void padata_parallel_worker(struct work_struct *work)
+static void padata_parallel_worker(struct work_struct *parallel_work)
{
- struct padata_queue *queue;
+ struct padata_parallel_queue *pqueue;
struct parallel_data *pd;
struct padata_instance *pinst;
LIST_HEAD(local_list);
local_bh_disable();
- queue = container_of(work, struct padata_queue, pwork);
- pd = queue->pd;
+ pqueue = container_of(parallel_work,
+ struct padata_parallel_queue, work);
+ pd = pqueue->pd;
pinst = pd->pinst;
- spin_lock(&queue->parallel.lock);
- list_replace_init(&queue->parallel.list, &local_list);
- spin_unlock(&queue->parallel.lock);
+ spin_lock(&pqueue->parallel.lock);
+ list_replace_init(&pqueue->parallel.list, &local_list);
+ spin_unlock(&pqueue->parallel.lock);
while (!list_empty(&local_list)) {
struct padata_priv *padata;
local_bh_enable();
}
-/*
+/**
* padata_do_parallel - padata parallelization function
*
* @pinst: padata instance
* @padata: object to be parallelized
* @cb_cpu: cpu the serialization callback function will run on,
- * must be in the cpumask of padata.
+ * must be in the serial cpumask of padata(i.e. cpumask.cbcpu).
*
* The parallelization callback function will run with BHs off.
* Note: Every object which is parallelized by padata_do_parallel
struct padata_priv *padata, int cb_cpu)
{
int target_cpu, err;
- struct padata_queue *queue;
+ struct padata_parallel_queue *queue;
struct parallel_data *pd;
rcu_read_lock_bh();
pd = rcu_dereference(pinst->pd);
- err = 0;
- if (!(pinst->flags & PADATA_INIT))
+ err = -EINVAL;
+ if (!(pinst->flags & PADATA_INIT) || pinst->flags & PADATA_INVALID)
+ goto out;
+
+ if (!cpumask_test_cpu(cb_cpu, pd->cpumask.cbcpu))
goto out;
err = -EBUSY;
if (atomic_read(&pd->refcnt) >= MAX_OBJ_NUM)
goto out;
- err = -EINVAL;
- if (!cpumask_test_cpu(cb_cpu, pd->cpumask))
- goto out;
-
- err = -EINPROGRESS;
+ err = 0;
atomic_inc(&pd->refcnt);
padata->pd = pd;
padata->cb_cpu = cb_cpu;
padata->seq_nr = atomic_inc_return(&pd->seq_nr);
target_cpu = padata_cpu_hash(padata);
- queue = per_cpu_ptr(pd->queue, target_cpu);
+ queue = per_cpu_ptr(pd->pqueue, target_cpu);
spin_lock(&queue->parallel.lock);
list_add_tail(&padata->list, &queue->parallel.list);
spin_unlock(&queue->parallel.lock);
- queue_work_on(target_cpu, pinst->wq, &queue->pwork);
+ queue_work_on(target_cpu, pinst->wq, &queue->work);
out:
rcu_read_unlock_bh();
}
EXPORT_SYMBOL(padata_do_parallel);
+/*
+ * padata_get_next - Get 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 all percpu reorder queues are empty.
+ *
+ * -EINPROGRESS, 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.
+ *
+ * -ENODATA, if this cpu has to do the parallel processing for
+ * the next object.
+ */
static struct padata_priv *padata_get_next(struct parallel_data *pd)
{
- int cpu, num_cpus, empty, calc_seq_nr;
- int seq_nr, next_nr, overrun, next_overrun;
- struct padata_queue *queue, *next_queue;
+ int cpu, num_cpus;
+ int next_nr, next_index;
+ struct padata_parallel_queue *queue, *next_queue;
struct padata_priv *padata;
struct padata_list *reorder;
- empty = 0;
- next_nr = -1;
- next_overrun = 0;
- next_queue = NULL;
-
- num_cpus = cpumask_weight(pd->cpumask);
-
- for_each_cpu(cpu, pd->cpumask) {
- queue = per_cpu_ptr(pd->queue, cpu);
- reorder = &queue->reorder;
-
- /*
- * Calculate the seq_nr of the object that should be
- * next in this queue.
- */
- overrun = 0;
- calc_seq_nr = (atomic_read(&queue->num_obj) * num_cpus)
- + queue->cpu_index;
-
- if (unlikely(calc_seq_nr > pd->max_seq_nr)) {
- calc_seq_nr = calc_seq_nr - pd->max_seq_nr - 1;
- overrun = 1;
- }
+ num_cpus = cpumask_weight(pd->cpumask.pcpu);
- if (!list_empty(&reorder->list)) {
- padata = list_entry(reorder->list.next,
- struct padata_priv, list);
-
- seq_nr = padata->seq_nr;
- BUG_ON(calc_seq_nr != seq_nr);
- } else {
- seq_nr = calc_seq_nr;
- empty++;
- }
-
- if (next_nr < 0 || seq_nr < next_nr
- || (next_overrun && !overrun)) {
- next_nr = seq_nr;
- next_overrun = overrun;
- next_queue = queue;
- }
+ /*
+ * Calculate the percpu reorder queue and the sequence
+ * number of the next object.
+ */
+ next_nr = pd->processed;
+ next_index = next_nr % num_cpus;
+ cpu = padata_index_to_cpu(pd, next_index);
+ next_queue = per_cpu_ptr(pd->pqueue, cpu);
+
+ if (unlikely(next_nr > pd->max_seq_nr)) {
+ next_nr = next_nr - pd->max_seq_nr - 1;
+ next_index = next_nr % num_cpus;
+ cpu = padata_index_to_cpu(pd, next_index);
+ next_queue = per_cpu_ptr(pd->pqueue, cpu);
+ pd->processed = 0;
}
padata = NULL;
- if (empty == num_cpus)
- goto out;
-
reorder = &next_queue->reorder;
if (!list_empty(&reorder->list)) {
padata = list_entry(reorder->list.next,
struct padata_priv, list);
- if (unlikely(next_overrun)) {
- for_each_cpu(cpu, pd->cpumask) {
- queue = per_cpu_ptr(pd->queue, cpu);
- atomic_set(&queue->num_obj, 0);
- }
- }
+ BUG_ON(next_nr != padata->seq_nr);
spin_lock(&reorder->lock);
list_del_init(&padata->list);
atomic_dec(&pd->reorder_objects);
spin_unlock(&reorder->lock);
- atomic_inc(&next_queue->num_obj);
+ pd->processed++;
goto out;
}
- if (next_nr % num_cpus == next_queue->cpu_index) {
+ queue = per_cpu_ptr(pd->pqueue, smp_processor_id());
+ if (queue->cpu_index == next_queue->cpu_index) {
padata = ERR_PTR(-ENODATA);
goto out;
}
static void padata_reorder(struct parallel_data *pd)
{
struct padata_priv *padata;
- struct padata_queue *queue;
+ struct padata_serial_queue *squeue;
struct padata_instance *pinst = pd->pinst;
-try_again:
+ /*
+ * We need to ensure that only one cpu can work on dequeueing of
+ * the reorder queue the time. Calculating in which percpu reorder
+ * queue the next object will arrive takes some time. A spinlock
+ * would be highly contended. Also it is not clear in which order
+ * the objects arrive to the reorder queues. So a cpu could wait to
+ * get the lock just to notice that there is nothing to do at the
+ * moment. Therefore we use a trylock and let the holder of the lock
+ * care for all the objects enqueued during the holdtime of the lock.
+ */
if (!spin_trylock_bh(&pd->lock))
- goto out;
+ return;
while (1) {
padata = padata_get_next(pd);
+ /*
+ * All reorder queues are empty, or the next object that needs
+ * serialization is parallel processed by another cpu and is
+ * still on it's way to the cpu's reorder queue, nothing to
+ * do for now.
+ */
if (!padata || PTR_ERR(padata) == -EINPROGRESS)
break;
+ /*
+ * This cpu has to do the parallel processing of the next
+ * object. It's waiting in the cpu's parallelization queue,
+ * so exit immediately.
+ */
if (PTR_ERR(padata) == -ENODATA) {
+ del_timer(&pd->timer);
spin_unlock_bh(&pd->lock);
- goto out;
+ return;
}
- queue = per_cpu_ptr(pd->queue, padata->cb_cpu);
+ squeue = per_cpu_ptr(pd->squeue, padata->cb_cpu);
- spin_lock(&queue->serial.lock);
- list_add_tail(&padata->list, &queue->serial.list);
- spin_unlock(&queue->serial.lock);
+ spin_lock(&squeue->serial.lock);
+ list_add_tail(&padata->list, &squeue->serial.list);
+ spin_unlock(&squeue->serial.lock);
- queue_work_on(padata->cb_cpu, pinst->wq, &queue->swork);
+ queue_work_on(padata->cb_cpu, pinst->wq, &squeue->work);
}
spin_unlock_bh(&pd->lock);
- if (atomic_read(&pd->reorder_objects))
- goto try_again;
+ /*
+ * The next object that needs serialization might have arrived to
+ * the reorder queues in the meantime, we will be called again
+ * from the timer function if no one else cares for it.
+ */
+ if (atomic_read(&pd->reorder_objects)
+ && !(pinst->flags & PADATA_RESET))
+ mod_timer(&pd->timer, jiffies + HZ);
+ else
+ del_timer(&pd->timer);
-out:
return;
}
-static void padata_serial_worker(struct work_struct *work)
+static void padata_reorder_timer(unsigned long arg)
+{
+ struct parallel_data *pd = (struct parallel_data *)arg;
+
+ padata_reorder(pd);
+}
+
+static void padata_serial_worker(struct work_struct *serial_work)
{
- struct padata_queue *queue;
+ struct padata_serial_queue *squeue;
struct parallel_data *pd;
LIST_HEAD(local_list);
local_bh_disable();
- queue = container_of(work, struct padata_queue, swork);
- pd = queue->pd;
+ squeue = container_of(serial_work, struct padata_serial_queue, work);
+ pd = squeue->pd;
- spin_lock(&queue->serial.lock);
- list_replace_init(&queue->serial.list, &local_list);
- spin_unlock(&queue->serial.lock);
+ spin_lock(&squeue->serial.lock);
+ list_replace_init(&squeue->serial.list, &local_list);
+ spin_unlock(&squeue->serial.lock);
while (!list_empty(&local_list)) {
struct padata_priv *padata;
local_bh_enable();
}
-/*
+/**
* padata_do_serial - padata serialization function
*
* @padata: object to be serialized.
void padata_do_serial(struct padata_priv *padata)
{
int cpu;
- struct padata_queue *queue;
+ struct padata_parallel_queue *pqueue;
struct parallel_data *pd;
pd = padata->pd;
cpu = get_cpu();
- queue = per_cpu_ptr(pd->queue, cpu);
+ pqueue = per_cpu_ptr(pd->pqueue, cpu);
- spin_lock(&queue->reorder.lock);
+ spin_lock(&pqueue->reorder.lock);
atomic_inc(&pd->reorder_objects);
- list_add_tail(&padata->list, &queue->reorder.list);
- spin_unlock(&queue->reorder.lock);
+ list_add_tail(&padata->list, &pqueue->reorder.list);
+ spin_unlock(&pqueue->reorder.lock);
put_cpu();
}
EXPORT_SYMBOL(padata_do_serial);
-static struct parallel_data *padata_alloc_pd(struct padata_instance *pinst,
- const struct cpumask *cpumask)
+static int padata_setup_cpumasks(struct parallel_data *pd,
+ const struct cpumask *pcpumask,
+ const struct cpumask *cbcpumask)
{
- int cpu, cpu_index, num_cpus;
- struct padata_queue *queue;
- struct parallel_data *pd;
-
- cpu_index = 0;
+ if (!alloc_cpumask_var(&pd->cpumask.pcpu, GFP_KERNEL))
+ return -ENOMEM;
- pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL);
- if (!pd)
- goto err;
+ cpumask_and(pd->cpumask.pcpu, pcpumask, cpu_active_mask);
+ if (!alloc_cpumask_var(&pd->cpumask.cbcpu, GFP_KERNEL)) {
+ free_cpumask_var(pd->cpumask.cbcpu);
+ return -ENOMEM;
+ }
- pd->queue = alloc_percpu(struct padata_queue);
- if (!pd->queue)
- goto err_free_pd;
+ cpumask_and(pd->cpumask.cbcpu, cbcpumask, cpu_active_mask);
+ return 0;
+}
- if (!alloc_cpumask_var(&pd->cpumask, GFP_KERNEL))
- goto err_free_queue;
+static void __padata_list_init(struct padata_list *pd_list)
+{
+ INIT_LIST_HEAD(&pd_list->list);
+ spin_lock_init(&pd_list->lock);
+}
- cpumask_and(pd->cpumask, cpumask, cpu_active_mask);
+/* Initialize all percpu queues used by serial workers */
+static void padata_init_squeues(struct parallel_data *pd)
+{
+ int cpu;
+ struct padata_serial_queue *squeue;
- for_each_cpu(cpu, pd->cpumask) {
- queue = per_cpu_ptr(pd->queue, cpu);
+ for_each_cpu(cpu, pd->cpumask.cbcpu) {
+ squeue = per_cpu_ptr(pd->squeue, cpu);
+ squeue->pd = pd;
+ __padata_list_init(&squeue->serial);
+ INIT_WORK(&squeue->work, padata_serial_worker);
+ }
+}
- queue->pd = pd;
+/* Initialize all percpu queues used by parallel workers */
+static void padata_init_pqueues(struct parallel_data *pd)
+{
+ int cpu_index, num_cpus, cpu;
+ struct padata_parallel_queue *pqueue;
- queue->cpu_index = cpu_index;
+ cpu_index = 0;
+ for_each_cpu(cpu, pd->cpumask.pcpu) {
+ pqueue = per_cpu_ptr(pd->pqueue, cpu);
+ pqueue->pd = pd;
+ pqueue->cpu_index = cpu_index;
cpu_index++;
- INIT_LIST_HEAD(&queue->reorder.list);
- INIT_LIST_HEAD(&queue->parallel.list);
- INIT_LIST_HEAD(&queue->serial.list);
- spin_lock_init(&queue->reorder.lock);
- spin_lock_init(&queue->parallel.lock);
- spin_lock_init(&queue->serial.lock);
-
- INIT_WORK(&queue->pwork, padata_parallel_worker);
- INIT_WORK(&queue->swork, padata_serial_worker);
- atomic_set(&queue->num_obj, 0);
+ __padata_list_init(&pqueue->reorder);
+ __padata_list_init(&pqueue->parallel);
+ INIT_WORK(&pqueue->work, padata_parallel_worker);
+ atomic_set(&pqueue->num_obj, 0);
}
- num_cpus = cpumask_weight(pd->cpumask);
- pd->max_seq_nr = (MAX_SEQ_NR / num_cpus) * num_cpus - 1;
+ num_cpus = cpumask_weight(pd->cpumask.pcpu);
+ pd->max_seq_nr = num_cpus ? (MAX_SEQ_NR / num_cpus) * num_cpus - 1 : 0;
+}
+
+/* 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)
+{
+ struct parallel_data *pd;
+ pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL);
+ if (!pd)
+ goto err;
+
+ pd->pqueue = alloc_percpu(struct padata_parallel_queue);
+ if (!pd->pqueue)
+ goto err_free_pd;
+
+ pd->squeue = alloc_percpu(struct padata_serial_queue);
+ if (!pd->squeue)
+ goto err_free_pqueue;
+ if (padata_setup_cpumasks(pd, pcpumask, cbcpumask) < 0)
+ goto err_free_squeue;
+
+ padata_init_pqueues(pd);
+ padata_init_squeues(pd);
+ setup_timer(&pd->timer, padata_reorder_timer, (unsigned long)pd);
atomic_set(&pd->seq_nr, -1);
atomic_set(&pd->reorder_objects, 0);
atomic_set(&pd->refcnt, 0);
return pd;
-err_free_queue:
- free_percpu(pd->queue);
+err_free_squeue:
+ free_percpu(pd->squeue);
+err_free_pqueue:
+ free_percpu(pd->pqueue);
err_free_pd:
kfree(pd);
err:
static void padata_free_pd(struct parallel_data *pd)
{
- free_cpumask_var(pd->cpumask);
- free_percpu(pd->queue);
+ free_cpumask_var(pd->cpumask.pcpu);
+ free_cpumask_var(pd->cpumask.cbcpu);
+ free_percpu(pd->pqueue);
+ free_percpu(pd->squeue);
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);
+ }
+
+ del_timer_sync(&pd->timer);
+
+ 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;
+}
+
+static void __padata_stop(struct padata_instance *pinst)
+{
+ if (!(pinst->flags & PADATA_INIT))
+ return;
+
+ 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)
{
struct parallel_data *pd_old = pinst->pd;
+ int notification_mask = 0;
pinst->flags |= PADATA_RESET;
synchronize_rcu();
- while (atomic_read(&pd_old->refcnt) != 0)
- yield();
-
- flush_workqueue(pinst->wq);
+ 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;
+ padata_flush_queues(pd_old);
padata_free_pd(pd_old);
+ if (notification_mask)
+ blocking_notifier_call_chain(&pinst->cpumask_change_notifier,
+ notification_mask,
+ &pd_new->cpumask);
+
pinst->flags &= ~PADATA_RESET;
}
-/*
- * padata_set_cpumask - set the cpumask that padata should use
+/**
+ * padata_register_cpumask_notifier - Registers a notifier that will be called
+ * if either pcpu or cbcpu or both cpumasks change.
*
- * @pinst: padata instance
- * @cpumask: the cpumask to use
+ * @pinst: A poineter to padata instance
+ * @nblock: A pointer to notifier block.
*/
-int padata_set_cpumask(struct padata_instance *pinst,
- cpumask_var_t cpumask)
+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);
+}
+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,
+ const struct cpumask *cpumask)
+{
+ if (!cpumask_intersects(cpumask, cpu_active_mask)) {
+ pinst->flags |= PADATA_INVALID;
+ return false;
+ }
+
+ pinst->flags &= ~PADATA_INVALID;
+ return true;
+}
+
+static int __padata_set_cpumasks(struct padata_instance *pinst,
+ cpumask_var_t pcpumask,
+ cpumask_var_t cbcpumask)
+{
+ int valid;
struct parallel_data *pd;
- int err = 0;
+
+ valid = padata_validate_cpumask(pinst, pcpumask);
+ if (!valid) {
+ __padata_stop(pinst);
+ goto out_replace;
+ }
+
+ valid = padata_validate_cpumask(pinst, cbcpumask);
+ if (!valid)
+ __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);
+
+ if (valid)
+ __padata_start(pinst);
+
+ return 0;
+}
+
+/**
+ * padata_set_cpumasks - Set both parallel and serial cpumasks. The first
+ * one is used by parallel workers and the second one
+ * by the wokers doing serialization.
+ *
+ * @pinst: padata instance
+ * @pcpumask: the cpumask to use for parallel workers
+ * @cbcpumask: the cpumsak to use for serial workers
+ */
+int padata_set_cpumasks(struct padata_instance *pinst, cpumask_var_t pcpumask,
+ cpumask_var_t cbcpumask)
+{
+ int err;
mutex_lock(&pinst->lock);
+ get_online_cpus();
+
+ err = __padata_set_cpumasks(pinst, pcpumask, cbcpumask);
+
+ put_online_cpus();
+ mutex_unlock(&pinst->lock);
+ return err;
+
+}
+EXPORT_SYMBOL(padata_set_cpumasks);
+
+/**
+ * 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
+ */
+int padata_set_cpumask(struct padata_instance *pinst, int cpumask_type,
+ cpumask_var_t cpumask)
+{
+ struct cpumask *serial_mask, *parallel_mask;
+ int err = -EINVAL;
+
+ mutex_lock(&pinst->lock);
get_online_cpus();
- pd = padata_alloc_pd(pinst, cpumask);
- if (!pd) {
- err = -ENOMEM;
- goto out;
+ switch (cpumask_type) {
+ case PADATA_CPU_PARALLEL:
+ serial_mask = pinst->cpumask.cbcpu;
+ parallel_mask = cpumask;
+ break;
+ case PADATA_CPU_SERIAL:
+ parallel_mask = pinst->cpumask.pcpu;
+ serial_mask = cpumask;
+ break;
+ default:
+ goto out;
}
- cpumask_copy(pinst->cpumask, cpumask);
-
- padata_replace(pinst, pd);
+ err = __padata_set_cpumasks(pinst, parallel_mask, serial_mask);
out:
put_online_cpus();
-
mutex_unlock(&pinst->lock);
return err;
struct parallel_data *pd;
if (cpumask_test_cpu(cpu, cpu_active_mask)) {
- pd = padata_alloc_pd(pinst, pinst->cpumask);
+ pd = padata_alloc_pd(pinst, pinst->cpumask.pcpu,
+ pinst->cpumask.cbcpu);
if (!pd)
return -ENOMEM;
padata_replace(pinst, pd);
+
+ if (padata_validate_cpumask(pinst, pinst->cpumask.pcpu) &&
+ padata_validate_cpumask(pinst, pinst->cpumask.cbcpu))
+ __padata_start(pinst);
}
return 0;
}
-/*
- * padata_add_cpu - add a cpu to the padata cpumask
+ /**
+ * padata_add_cpu - add a cpu to one or both(parallel and serial)
+ * padata cpumasks.
*
* @pinst: padata instance
* @cpu: cpu to add
+ * @mask: bitmask of flags specifying to which cpumask @cpu shuld be added.
+ * The @mask may be any combination of the following flags:
+ * PADATA_CPU_SERIAL - serial cpumask
+ * PADATA_CPU_PARALLEL - parallel cpumask
*/
-int padata_add_cpu(struct padata_instance *pinst, int cpu)
+
+int padata_add_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();
- cpumask_set_cpu(cpu, pinst->cpumask);
+ if (mask & PADATA_CPU_SERIAL)
+ cpumask_set_cpu(cpu, pinst->cpumask.cbcpu);
+ if (mask & PADATA_CPU_PARALLEL)
+ cpumask_set_cpu(cpu, pinst->cpumask.pcpu);
+
err = __padata_add_cpu(pinst, cpu);
put_online_cpus();
static int __padata_remove_cpu(struct padata_instance *pinst, int cpu)
{
- struct parallel_data *pd;
+ struct parallel_data *pd = NULL;
if (cpumask_test_cpu(cpu, cpu_online_mask)) {
- pd = padata_alloc_pd(pinst, pinst->cpumask);
+
+ 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;
return 0;
}
-/*
- * padata_remove_cpu - remove a cpu from the padata cpumask
+ /**
+ * 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 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();
- cpumask_clear_cpu(cpu, pinst->cpumask);
+ 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();
}
EXPORT_SYMBOL(padata_remove_cpu);
-/*
+/**
* padata_start - start the parallel processing
*
* @pinst: padata instance to start
*/
-void padata_start(struct padata_instance *pinst)
+int padata_start(struct padata_instance *pinst)
{
+ int err = 0;
+
mutex_lock(&pinst->lock);
- pinst->flags |= PADATA_INIT;
+
+ if (pinst->flags & PADATA_INVALID)
+ err =-EINVAL;
+
+ __padata_start(pinst);
+
mutex_unlock(&pinst->lock);
+
+ return err;
}
EXPORT_SYMBOL(padata_start);
-/*
+/**
* padata_stop - stop the parallel processing
*
* @pinst: padata instance to stop
void padata_stop(struct padata_instance *pinst)
{
mutex_lock(&pinst->lock);
- pinst->flags &= ~PADATA_INIT;
+ __padata_stop(pinst);
mutex_unlock(&pinst->lock);
}
EXPORT_SYMBOL(padata_stop);
#ifdef CONFIG_HOTPLUG_CPU
+
+static inline int pinst_has_cpu(struct padata_instance *pinst, int cpu)
+{
+ return cpumask_test_cpu(cpu, pinst->cpumask.pcpu) ||
+ cpumask_test_cpu(cpu, pinst->cpumask.cbcpu);
+}
+
+
static int padata_cpu_callback(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
switch (action) {
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
- if (!cpumask_test_cpu(cpu, pinst->cpumask))
+ if (!pinst_has_cpu(pinst, cpu))
break;
mutex_lock(&pinst->lock);
err = __padata_add_cpu(pinst, cpu);
mutex_unlock(&pinst->lock);
if (err)
- return NOTIFY_BAD;
+ return notifier_from_errno(err);
break;
case CPU_DOWN_PREPARE:
case CPU_DOWN_PREPARE_FROZEN:
- if (!cpumask_test_cpu(cpu, pinst->cpumask))
+ if (!pinst_has_cpu(pinst, cpu))
break;
mutex_lock(&pinst->lock);
err = __padata_remove_cpu(pinst, cpu);
mutex_unlock(&pinst->lock);
if (err)
- return NOTIFY_BAD;
+ return notifier_from_errno(err);
break;
case CPU_UP_CANCELED:
case CPU_UP_CANCELED_FROZEN:
- if (!cpumask_test_cpu(cpu, pinst->cpumask))
+ if (!pinst_has_cpu(pinst, cpu))
break;
mutex_lock(&pinst->lock);
__padata_remove_cpu(pinst, cpu);
case CPU_DOWN_FAILED:
case CPU_DOWN_FAILED_FROZEN:
- if (!cpumask_test_cpu(cpu, pinst->cpumask))
+ if (!pinst_has_cpu(pinst, cpu))
break;
mutex_lock(&pinst->lock);
__padata_add_cpu(pinst, cpu);
}
#endif
+static void __padata_free(struct padata_instance *pinst)
+{
+#ifdef CONFIG_HOTPLUG_CPU
+ unregister_hotcpu_notifier(&pinst->cpu_notifier);
+#endif
+
+ padata_stop(pinst);
+ padata_free_pd(pinst->pd);
+ free_cpumask_var(pinst->cpumask.pcpu);
+ free_cpumask_var(pinst->cpumask.cbcpu);
+ kfree(pinst);
+}
+
+#define kobj2pinst(_kobj) \
+ container_of(_kobj, struct padata_instance, kobj)
+#define attr2pentry(_attr) \
+ container_of(_attr, struct padata_sysfs_entry, attr)
+
+static void padata_sysfs_release(struct kobject *kobj)
+{
+ struct padata_instance *pinst = kobj2pinst(kobj);
+ __padata_free(pinst);
+}
+
+struct padata_sysfs_entry {
+ struct attribute attr;
+ ssize_t (*show)(struct padata_instance *, struct attribute *, char *);
+ ssize_t (*store)(struct padata_instance *, struct attribute *,
+ const char *, size_t);
+};
+
+static ssize_t show_cpumask(struct padata_instance *pinst,
+ struct attribute *attr, char *buf)
+{
+ struct cpumask *cpumask;
+ ssize_t len;
+
+ mutex_lock(&pinst->lock);
+ if (!strcmp(attr->name, "serial_cpumask"))
+ cpumask = pinst->cpumask.cbcpu;
+ else
+ cpumask = pinst->cpumask.pcpu;
+
+ len = bitmap_scnprintf(buf, PAGE_SIZE, cpumask_bits(cpumask),
+ nr_cpu_ids);
+ if (PAGE_SIZE - len < 2)
+ len = -EINVAL;
+ else
+ len += sprintf(buf + len, "\n");
+
+ mutex_unlock(&pinst->lock);
+ return len;
+}
+
+static ssize_t store_cpumask(struct padata_instance *pinst,
+ struct attribute *attr,
+ const char *buf, size_t count)
+{
+ cpumask_var_t new_cpumask;
+ ssize_t ret;
+ int mask_type;
+
+ if (!alloc_cpumask_var(&new_cpumask, GFP_KERNEL))
+ return -ENOMEM;
+
+ ret = bitmap_parse(buf, count, cpumask_bits(new_cpumask),
+ nr_cpumask_bits);
+ if (ret < 0)
+ goto out;
+
+ mask_type = !strcmp(attr->name, "serial_cpumask") ?
+ PADATA_CPU_SERIAL : PADATA_CPU_PARALLEL;
+ ret = padata_set_cpumask(pinst, mask_type, new_cpumask);
+ if (!ret)
+ ret = count;
+
+out:
+ free_cpumask_var(new_cpumask);
+ return ret;
+}
+
+#define PADATA_ATTR_RW(_name, _show_name, _store_name) \
+ static struct padata_sysfs_entry _name##_attr = \
+ __ATTR(_name, 0644, _show_name, _store_name)
+#define PADATA_ATTR_RO(_name, _show_name) \
+ static struct padata_sysfs_entry _name##_attr = \
+ __ATTR(_name, 0400, _show_name, NULL)
+
+PADATA_ATTR_RW(serial_cpumask, show_cpumask, store_cpumask);
+PADATA_ATTR_RW(parallel_cpumask, show_cpumask, store_cpumask);
+
/*
- * padata_alloc - allocate and initialize a padata instance
+ * Padata sysfs provides the following objects:
+ * serial_cpumask [RW] - cpumask for serial workers
+ * parallel_cpumask [RW] - cpumask for parallel workers
+ */
+static struct attribute *padata_default_attrs[] = {
+ &serial_cpumask_attr.attr,
+ ¶llel_cpumask_attr.attr,
+ NULL,
+};
+
+static ssize_t padata_sysfs_show(struct kobject *kobj,
+ struct attribute *attr, char *buf)
+{
+ struct padata_instance *pinst;
+ struct padata_sysfs_entry *pentry;
+ ssize_t ret = -EIO;
+
+ pinst = kobj2pinst(kobj);
+ pentry = attr2pentry(attr);
+ if (pentry->show)
+ ret = pentry->show(pinst, attr, buf);
+
+ return ret;
+}
+
+static ssize_t padata_sysfs_store(struct kobject *kobj, struct attribute *attr,
+ const char *buf, size_t count)
+{
+ struct padata_instance *pinst;
+ struct padata_sysfs_entry *pentry;
+ ssize_t ret = -EIO;
+
+ pinst = kobj2pinst(kobj);
+ pentry = attr2pentry(attr);
+ if (pentry->show)
+ ret = pentry->store(pinst, attr, buf, count);
+
+ return ret;
+}
+
+static const struct sysfs_ops padata_sysfs_ops = {
+ .show = padata_sysfs_show,
+ .store = padata_sysfs_store,
+};
+
+static struct kobj_type padata_attr_type = {
+ .sysfs_ops = &padata_sysfs_ops,
+ .default_attrs = padata_default_attrs,
+ .release = padata_sysfs_release,
+};
+
+/**
+ * padata_alloc_possible - Allocate and initialize padata instance.
+ * Use the cpu_possible_mask for serial and
+ * parallel workers.
*
- * @cpumask: cpumask that padata uses for parallelization
* @wq: workqueue to use for the allocated padata instance
*/
-struct padata_instance *padata_alloc(const struct cpumask *cpumask,
- struct workqueue_struct *wq)
+struct padata_instance *padata_alloc_possible(struct workqueue_struct *wq)
+{
+ return padata_alloc(wq, cpu_possible_mask, cpu_possible_mask);
+}
+EXPORT_SYMBOL(padata_alloc_possible);
+
+/**
+ * padata_alloc - allocate and initialize a padata instance and specify
+ * cpumasks for serial and parallel workers.
+ *
+ * @wq: workqueue to use for the allocated padata instance
+ * @pcpumask: cpumask that will be used for padata parallelization
+ * @cbcpumask: cpumask that will be used for padata serialization
+ */
+struct padata_instance *padata_alloc(struct workqueue_struct *wq,
+ const struct cpumask *pcpumask,
+ const struct cpumask *cbcpumask)
{
struct padata_instance *pinst;
- struct parallel_data *pd;
+ struct parallel_data *pd = NULL;
pinst = kzalloc(sizeof(struct padata_instance), GFP_KERNEL);
if (!pinst)
goto err;
get_online_cpus();
-
- pd = padata_alloc_pd(pinst, cpumask);
- if (!pd)
+ if (!alloc_cpumask_var(&pinst->cpumask.pcpu, GFP_KERNEL))
goto err_free_inst;
+ if (!alloc_cpumask_var(&pinst->cpumask.cbcpu, GFP_KERNEL)) {
+ free_cpumask_var(pinst->cpumask.pcpu);
+ goto err_free_inst;
+ }
+ if (!padata_validate_cpumask(pinst, pcpumask) ||
+ !padata_validate_cpumask(pinst, cbcpumask))
+ goto err_free_masks;
- if (!alloc_cpumask_var(&pinst->cpumask, GFP_KERNEL))
- goto err_free_pd;
+ pd = padata_alloc_pd(pinst, pcpumask, cbcpumask);
+ if (!pd)
+ goto err_free_masks;
rcu_assign_pointer(pinst->pd, pd);
pinst->wq = wq;
- cpumask_copy(pinst->cpumask, cpumask);
+ cpumask_copy(pinst->cpumask.pcpu, pcpumask);
+ cpumask_copy(pinst->cpumask.cbcpu, cbcpumask);
pinst->flags = 0;
put_online_cpus();
+ BLOCKING_INIT_NOTIFIER_HEAD(&pinst->cpumask_change_notifier);
+ kobject_init(&pinst->kobj, &padata_attr_type);
mutex_init(&pinst->lock);
return pinst;
-err_free_pd:
- padata_free_pd(pd);
+err_free_masks:
+ free_cpumask_var(pinst->cpumask.pcpu);
+ free_cpumask_var(pinst->cpumask.cbcpu);
err_free_inst:
kfree(pinst);
put_online_cpus();
}
EXPORT_SYMBOL(padata_alloc);
-/*
+/**
* padata_free - free a padata instance
*
- * @ padata_inst: padata instance to free
+ * @padata_inst: padata instance to free
*/
void padata_free(struct padata_instance *pinst)
{
- padata_stop(pinst);
-
- synchronize_rcu();
-
- while (atomic_read(&pinst->pd->refcnt) != 0)
- yield();
-
-#ifdef CONFIG_HOTPLUG_CPU
- unregister_hotcpu_notifier(&pinst->cpu_notifier);
-#endif
- padata_free_pd(pinst->pd);
- free_cpumask_var(pinst->cpumask);
- kfree(pinst);
+ kobject_put(&pinst->kobj);
}
EXPORT_SYMBOL(padata_free);
Code Review / linux-2.6.git / blobdiff