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Commit 7fc2ba17 authored by Shaohua Li's avatar Shaohua Li Committed by Jens Axboe
Browse files

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: default avatarShaohua Li <shli@fusionio.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent e26b53d0

include/linux/percpu_ida.h

+4 −0
Original line number Original line Diff line number Diff line
@@ -73,4 +73,8 @@ static inline int percpu_ida_init(struct percpu_ida *pool, unsigned long nr_tags 
		IDA_DEFAULT_PCPU_BATCH_MOVE);

		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__ */
 
#endif /* __PERCPU_IDA_H__ */

lib/percpu_ida.c

+44 −0
Original line number Original line Diff line number Diff line
@@ -327,3 +327,47 @@ int __percpu_ida_init(struct percpu_ida *pool, unsigned long nr_tags, 
	return -ENOMEM;

	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);