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.
Signed-off-by: Shaohua Li <[email protected]> --- include/linux/percpu_ida.h | 4 ++++ lib/percpu_ida.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 48 insertions(+) Index: master/include/linux/percpu_ida.h =================================================================== --- master.orig/include/linux/percpu_ida.h 2013-10-15 08:28:36.198031207 +0800 +++ master/include/linux/percpu_ida.h 2013-10-15 08:30:19.996733244 +0800 @@ -73,4 +73,8 @@ static inline int percpu_ida_init(struct 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__ */ Index: master/lib/percpu_ida.c =================================================================== --- master.orig/lib/percpu_ida.c 2013-10-15 08:28:36.198031207 +0800 +++ master/lib/percpu_ida.c 2013-10-15 08:40:06.937353699 +0800 @@ -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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
