diff options
author | Shaohua Li <shli@kernel.org> | 2013-10-15 03:05:02 +0200 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2013-10-25 12:55:59 +0200 |
commit | 7fc2ba17e8bf9f218cac10cc2a3de613d9d9086d (patch) | |
tree | 464baa951977743dc1da2dd1a0f595c50dc3e0a8 | |
parent | percpu_ida: make percpu_ida percpu size/batch configurable (diff) | |
download | linux-7fc2ba17e8bf9f218cac10cc2a3de613d9d9086d.tar.xz linux-7fc2ba17e8bf9f218cac10cc2a3de613d9d9086d.zip |
percpu_ida: add percpu_ida_for_each_free
Add a new API to iterate free ids. blk-mq-tag will use it.
Note, this doesn't guarantee to iterate all free ids restrictly. Caller
should be aware of this. blk-mq uses it to do sanity check for request
timedout, so can tolerate the limitation.
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r-- | include/linux/percpu_ida.h | 4 | ||||
-rw-r--r-- | lib/percpu_ida.c | 44 |
2 files changed, 48 insertions, 0 deletions
diff --git a/include/linux/percpu_ida.h b/include/linux/percpu_ida.h index 56c14033e7e7..63510ae6f933 100644 --- a/include/linux/percpu_ida.h +++ b/include/linux/percpu_ida.h @@ -73,4 +73,8 @@ static inline int percpu_ida_init(struct percpu_ida *pool, unsigned long nr_tags IDA_DEFAULT_PCPU_BATCH_MOVE); } +typedef int (*percpu_ida_cb)(unsigned, void *); +int percpu_ida_for_each_free(struct percpu_ida *pool, percpu_ida_cb fn, + void *data); + #endif /* __PERCPU_IDA_H__ */ diff --git a/lib/percpu_ida.c b/lib/percpu_ida.c index a601d4259e13..0f51c1b556cf 100644 --- a/lib/percpu_ida.c +++ b/lib/percpu_ida.c @@ -327,3 +327,47 @@ err: return -ENOMEM; } 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); |