Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754548Ab3JXJ1e (ORCPT ); Thu, 24 Oct 2013 05:27:34 -0400 Received: from merlin.infradead.org ([205.233.59.134]:36743 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754547Ab3JXJ0W (ORCPT ); Thu, 24 Oct 2013 05:26:22 -0400 From: Jens Axboe To: linux-kernel@vger.kernel.org Cc: hch@infradead.org, Shaohua Li , Andrew Morton , Shaohua Li , Jens Axboe Subject: [PATCH 08/11] percpu_ida: add percpu_ida_for_each_free Date: Thu, 24 Oct 2013 10:26:01 +0100 Message-Id: <1382606764-8309-9-git-send-email-axboe@kernel.dk> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1382606764-8309-1-git-send-email-axboe@kernel.dk> References: <1382606764-8309-1-git-send-email-axboe@kernel.dk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2609 Lines: 89 From: Shaohua Li 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 Signed-off-by: Shaohua Li Signed-off-by: Jens Axboe --- include/linux/percpu_ida.h | 4 ++++ lib/percpu_ida.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 48 insertions(+) diff --git a/include/linux/percpu_ida.h b/include/linux/percpu_ida.h index 56c1403..63510ae 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 a601d42..0f51c1b 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); -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/