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authorJens Axboe <axboe@kernel.dk>2013-11-08 09:08:12 -0700
committerJens Axboe <axboe@kernel.dk>2013-11-08 09:08:12 -0700
commite37459b8e2c7db6735e39e019e448b76e5e77647 (patch)
treea3f0944db87a8ae0d41e5acbbbabc1e7ef534d1b /lib
parentc7d1ba417c7cb7297d14dd47a390ec90ce548d5c (diff)
parente7e245000110a7794de8f925b9edc06a9c852f80 (diff)
Merge branch 'blk-mq/core' into for-3.13/core
Signed-off-by: Jens Axboe <axboe@kernel.dk> Conflicts: block/blk-timeout.c
Diffstat (limited to 'lib')
-rw-r--r--lib/percpu_counter.c15
-rw-r--r--lib/percpu_ida.c89
2 files changed, 81 insertions, 23 deletions
diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c
index 93c5d5ecff4e..7473ee3b4ee7 100644
--- a/lib/percpu_counter.c
+++ b/lib/percpu_counter.c
@@ -60,14 +60,15 @@ static inline void debug_percpu_counter_deactivate(struct percpu_counter *fbc)
void percpu_counter_set(struct percpu_counter *fbc, s64 amount)
{
int cpu;
+ unsigned long flags;
- raw_spin_lock(&fbc->lock);
+ raw_spin_lock_irqsave(&fbc->lock, flags);
for_each_possible_cpu(cpu) {
s32 *pcount = per_cpu_ptr(fbc->counters, cpu);
*pcount = 0;
}
fbc->count = amount;
- raw_spin_unlock(&fbc->lock);
+ raw_spin_unlock_irqrestore(&fbc->lock, flags);
}
EXPORT_SYMBOL(percpu_counter_set);
@@ -78,9 +79,10 @@ void __percpu_counter_add(struct percpu_counter *fbc, s64 amount, s32 batch)
preempt_disable();
count = __this_cpu_read(*fbc->counters) + amount;
if (count >= batch || count <= -batch) {
- raw_spin_lock(&fbc->lock);
+ unsigned long flags;
+ raw_spin_lock_irqsave(&fbc->lock, flags);
fbc->count += count;
- raw_spin_unlock(&fbc->lock);
+ raw_spin_unlock_irqrestore(&fbc->lock, flags);
__this_cpu_write(*fbc->counters, 0);
} else {
__this_cpu_write(*fbc->counters, count);
@@ -97,14 +99,15 @@ s64 __percpu_counter_sum(struct percpu_counter *fbc)
{
s64 ret;
int cpu;
+ unsigned long flags;
- raw_spin_lock(&fbc->lock);
+ raw_spin_lock_irqsave(&fbc->lock, flags);
ret = fbc->count;
for_each_online_cpu(cpu) {
s32 *pcount = per_cpu_ptr(fbc->counters, cpu);
ret += *pcount;
}
- raw_spin_unlock(&fbc->lock);
+ raw_spin_unlock_irqrestore(&fbc->lock, flags);
return ret;
}
EXPORT_SYMBOL(__percpu_counter_sum);
diff --git a/lib/percpu_ida.c b/lib/percpu_ida.c
index bab1ba2a4c71..b0698ea972c6 100644
--- a/lib/percpu_ida.c
+++ b/lib/percpu_ida.c
@@ -30,15 +30,6 @@
#include <linux/spinlock.h>
#include <linux/percpu_ida.h>
-/*
- * Number of tags we move between the percpu freelist and the global freelist at
- * a time
- */
-#define IDA_PCPU_BATCH_MOVE 32U
-
-/* Max size of percpu freelist, */
-#define IDA_PCPU_SIZE ((IDA_PCPU_BATCH_MOVE * 3) / 2)
-
struct percpu_ida_cpu {
/*
* Even though this is percpu, we need a lock for tag stealing by remote
@@ -78,7 +69,7 @@ static inline void steal_tags(struct percpu_ida *pool,
struct percpu_ida_cpu *remote;
for (cpus_have_tags = cpumask_weight(&pool->cpus_have_tags);
- cpus_have_tags * IDA_PCPU_SIZE > pool->nr_tags / 2;
+ cpus_have_tags * pool->percpu_max_size > pool->nr_tags / 2;
cpus_have_tags--) {
cpu = cpumask_next(cpu, &pool->cpus_have_tags);
@@ -123,7 +114,7 @@ static inline void alloc_global_tags(struct percpu_ida *pool,
{
move_tags(tags->freelist, &tags->nr_free,
pool->freelist, &pool->nr_free,
- min(pool->nr_free, IDA_PCPU_BATCH_MOVE));
+ min(pool->nr_free, pool->percpu_batch_size));
}
static inline unsigned alloc_local_tag(struct percpu_ida *pool,
@@ -245,17 +236,17 @@ void percpu_ida_free(struct percpu_ida *pool, unsigned tag)
wake_up(&pool->wait);
}
- if (nr_free == IDA_PCPU_SIZE) {
+ if (nr_free == pool->percpu_max_size) {
spin_lock(&pool->lock);
/*
* Global lock held and irqs disabled, don't need percpu
* lock
*/
- if (tags->nr_free == IDA_PCPU_SIZE) {
+ if (tags->nr_free == pool->percpu_max_size) {
move_tags(pool->freelist, &pool->nr_free,
tags->freelist, &tags->nr_free,
- IDA_PCPU_BATCH_MOVE);
+ pool->percpu_batch_size);
wake_up(&pool->wait);
}
@@ -292,7 +283,8 @@ EXPORT_SYMBOL_GPL(percpu_ida_destroy);
* Allocation is percpu, but sharding is limited by nr_tags - for best
* performance, the workload should not span more cpus than nr_tags / 128.
*/
-int percpu_ida_init(struct percpu_ida *pool, unsigned long nr_tags)
+int __percpu_ida_init(struct percpu_ida *pool, unsigned long nr_tags,
+ unsigned long max_size, unsigned long batch_size)
{
unsigned i, cpu, order;
@@ -301,6 +293,8 @@ int percpu_ida_init(struct percpu_ida *pool, unsigned long nr_tags)
init_waitqueue_head(&pool->wait);
spin_lock_init(&pool->lock);
pool->nr_tags = nr_tags;
+ pool->percpu_max_size = max_size;
+ pool->percpu_batch_size = batch_size;
/* Guard against overflow */
if (nr_tags > (unsigned) INT_MAX + 1) {
@@ -319,7 +313,7 @@ int percpu_ida_init(struct percpu_ida *pool, unsigned long nr_tags)
pool->nr_free = nr_tags;
pool->tag_cpu = __alloc_percpu(sizeof(struct percpu_ida_cpu) +
- IDA_PCPU_SIZE * sizeof(unsigned),
+ pool->percpu_max_size * sizeof(unsigned),
sizeof(unsigned));
if (!pool->tag_cpu)
goto err;
@@ -332,4 +326,65 @@ err:
percpu_ida_destroy(pool);
return -ENOMEM;
}
-EXPORT_SYMBOL_GPL(percpu_ida_init);
+EXPORT_SYMBOL_GPL(__percpu_ida_init);
+
+/**
+ * percpu_ida_for_each_free - iterate free ids of a pool
+ * @pool: pool to iterate
+ * @fn: interate callback function
+ * @data: parameter for @fn
+ *
+ * Note, this doesn't guarantee to iterate all free ids restrictly. Some free
+ * ids might be missed, some might be iterated duplicated, and some might
+ * be iterated and not free soon.
+ */
+int percpu_ida_for_each_free(struct percpu_ida *pool, percpu_ida_cb fn,
+ void *data)
+{
+ unsigned long flags;
+ struct percpu_ida_cpu *remote;
+ unsigned cpu, i, err = 0;
+
+ local_irq_save(flags);
+ for_each_possible_cpu(cpu) {
+ remote = per_cpu_ptr(pool->tag_cpu, cpu);
+ spin_lock(&remote->lock);
+ for (i = 0; i < remote->nr_free; i++) {
+ err = fn(remote->freelist[i], data);
+ if (err)
+ break;
+ }
+ spin_unlock(&remote->lock);
+ if (err)
+ goto out;
+ }
+
+ spin_lock(&pool->lock);
+ for (i = 0; i < pool->nr_free; i++) {
+ err = fn(pool->freelist[i], data);
+ if (err)
+ break;
+ }
+ spin_unlock(&pool->lock);
+out:
+ local_irq_restore(flags);
+ return err;
+}
+EXPORT_SYMBOL_GPL(percpu_ida_for_each_free);
+
+/**
+ * percpu_ida_free_tags - return free tags number of a specific cpu or global pool
+ * @pool: pool related
+ * @cpu: specific cpu or global pool if @cpu == nr_cpu_ids
+ *
+ * Note: this just returns a snapshot of free tags number.
+ */
+unsigned percpu_ida_free_tags(struct percpu_ida *pool, int cpu)
+{
+ struct percpu_ida_cpu *remote;
+ if (cpu == nr_cpu_ids)
+ return pool->nr_free;
+ remote = per_cpu_ptr(pool->tag_cpu, cpu);
+ return remote->nr_free;
+}
+EXPORT_SYMBOL_GPL(percpu_ida_free_tags);