Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752594AbbL1TME (ORCPT ); Mon, 28 Dec 2015 14:12:04 -0500 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:57841 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751412AbbL1TMC (ORCPT ); Mon, 28 Dec 2015 14:12:02 -0500 Subject: Re: [PATCH] null_blk: don't enable irqs when in irq To: Rabin Vincent References: <1451053594-12188-1-git-send-email-rabin@rab.in> <567E1180.8070004@fb.com> <568184E8.1080801@fb.com> <20151228190715.GA20883@debian> CC: From: Jens Axboe Message-ID: <56818955.8030401@fb.com> Date: Mon, 28 Dec 2015 12:11:17 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <20151228190715.GA20883@debian> Content-Type: multipart/mixed; boundary="------------000203090707050104050308" X-Originating-IP: [192.168.54.13] X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2015-12-28_13:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3392 Lines: 103 --------------000203090707050104050308 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit On 12/28/2015 12:07 PM, Rabin Vincent wrote: > On Mon, Dec 28, 2015 at 11:52:24AM -0700, Jens Axboe wrote: >> Something like this should work, can you test it? > > Spits out a bunch of the following. It's this assertion: > > static inline void queue_lockdep_assert_held(struct request_queue *q) > { > if (q->queue_lock) > lockdep_assert_held(q->queue_lock); > } Ah right, we clear the stopped flag. This one should be better. -- Jens Axboe --------------000203090707050104050308 Content-Type: text/x-patch; name="null-restart-v2.patch" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="null-restart-v2.patch" diff --git a/block/blk-core.c b/block/blk-core.c index c487b94c59e3..33e2f62d5062 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -207,6 +207,22 @@ void blk_delay_queue(struct request_queue *q, unsigned long msecs) EXPORT_SYMBOL(blk_delay_queue); /** + * blk_start_queue_async - asynchronously restart a previously stopped queue + * @q: The &struct request_queue in question + * + * Description: + * blk_start_queue_async() will clear the stop flag on the queue, and + * ensure that the request_fn for the queue is run from an async + * context. + **/ +void blk_start_queue_async(struct request_queue *q) +{ + queue_flag_clear(QUEUE_FLAG_STOPPED, q); + blk_run_queue_async(q); +} +EXPORT_SYMBOL(blk_start_queue_async); + +/** * blk_start_queue - restart a previously stopped queue * @q: The &struct request_queue in question * diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c index a428e4ef71fd..09e3c0d87ecc 100644 --- a/drivers/block/null_blk.c +++ b/drivers/block/null_blk.c @@ -232,20 +232,19 @@ static void end_cmd(struct nullb_cmd *cmd) break; case NULL_Q_BIO: bio_endio(cmd->bio); - goto free_cmd; + break; } + free_cmd(cmd); + /* Restart queue if needed, as we are freeing a tag */ - if (q && !q->mq_ops && blk_queue_stopped(q)) { + if (queue_mode == NULL_Q_RQ && blk_queue_stopped(q)) { unsigned long flags; spin_lock_irqsave(q->queue_lock, flags); - if (blk_queue_stopped(q)) - blk_start_queue(q); + blk_start_queue_async(q); spin_unlock_irqrestore(q->queue_lock, flags); } -free_cmd: - free_cmd(cmd); } static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 0169ba2e2e64..c70e3588a48c 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -797,6 +797,7 @@ extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t, extern int blk_queue_enter(struct request_queue *q, gfp_t gfp); extern void blk_queue_exit(struct request_queue *q); extern void blk_start_queue(struct request_queue *q); +extern void blk_start_queue_async(struct request_queue *q); extern void blk_stop_queue(struct request_queue *q); extern void blk_sync_queue(struct request_queue *q); extern void __blk_stop_queue(struct request_queue *q); --------------000203090707050104050308-- -- 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/