Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...

[~andy/linux] / lib / percpu_ida.c

diff --git a/lib/percpu_ida.c b/lib/percpu_ida.c
index 9d054bf91d0f3cd278494dedd3114dfd3b292bcb..93d145e5539c2e1bd0a9e8fc014739c178e6d0fc 100644 (file)
--- a/lib/percpu_ida.c
+++ b/lib/percpu_ida.c
@@ -54,9 +54,7 @@ static inline void move_tags(unsigned *dst, unsigned *dst_nr,
 /*
  * Try to steal tags from a remote cpu's percpu freelist.
  *
- * We first check how many percpu freelists have tags - we don't steal tags
- * unless enough percpu freelists have tags on them that it's possible more than
- * half the total tags could be stuck on remote percpu freelists.
+ * We first check how many percpu freelists have tags
  *
  * Then we iterate through the cpus until we find some tags - we don't attempt
  * to find the "best" cpu to steal from, to keep cacheline bouncing to a
@@ -69,8 +67,7 @@ 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 * pool->percpu_max_size > pool->nr_tags / 2;
-            cpus_have_tags--) {
+            cpus_have_tags; cpus_have_tags--) {
                cpu = cpumask_next(cpu, &pool->cpus_have_tags);
 
                if (cpu >= nr_cpu_ids) {
@@ -132,22 +129,22 @@ static inline unsigned alloc_local_tag(struct percpu_ida_cpu *tags)
 /**
  * percpu_ida_alloc - allocate a tag
  * @pool: pool to allocate from
- * @gfp: gfp flags
+ * @state: task state for prepare_to_wait
  *
  * Returns a tag - an integer in the range [0..nr_tags) (passed to
  * tag_pool_init()), or otherwise -ENOSPC on allocation failure.
  *
  * Safe to be called from interrupt context (assuming it isn't passed
- * __GFP_WAIT, of course).
+ * TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, of course).
  *
  * @gfp indicates whether or not to wait until a free id is available (it's not
  * used for internal memory allocations); thus if passed __GFP_WAIT we may sleep
  * however long it takes until another thread frees an id (same semantics as a
  * mempool).
  *
- * Will not fail if passed __GFP_WAIT.
+ * Will not fail if passed TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE.
  */
-int percpu_ida_alloc(struct percpu_ida *pool, gfp_t gfp)
+int percpu_ida_alloc(struct percpu_ida *pool, int state)
 {
        DEFINE_WAIT(wait);
        struct percpu_ida_cpu *tags;
@@ -174,7 +171,8 @@ int percpu_ida_alloc(struct percpu_ida *pool, gfp_t gfp)
                 *
                 * global lock held and irqs disabled, don't need percpu lock
                 */
-               prepare_to_wait(&pool->wait, &wait, TASK_UNINTERRUPTIBLE);
+               if (state != TASK_RUNNING)
+                       prepare_to_wait(&pool->wait, &wait, state);
 
                if (!tags->nr_free)
                        alloc_global_tags(pool, tags);
@@ -191,16 +189,22 @@ int percpu_ida_alloc(struct percpu_ida *pool, gfp_t gfp)
                spin_unlock(&pool->lock);
                local_irq_restore(flags);
 
-               if (tag >= 0 || !(gfp & __GFP_WAIT))
+               if (tag >= 0 || state == TASK_RUNNING)
                        break;
 
+               if (signal_pending_state(state, current)) {
+                       tag = -ERESTARTSYS;
+                       break;
+               }
+
                schedule();
 
                local_irq_save(flags);
                tags = this_cpu_ptr(pool->tag_cpu);
        }
+       if (state != TASK_RUNNING)
+               finish_wait(&pool->wait, &wait);
 
-       finish_wait(&pool->wait, &wait);
        return tag;
 }
 EXPORT_SYMBOL_GPL(percpu_ida_alloc);