From: Bart Van Assche <bvanassche@acm.org>
To: Tejun Heo <tj@kernel.org>
Cc: linux-scsi <linux-scsi@vger.kernel.org>,
James Bottomley <jbottomley@parallels.com>,
Mike Christie <michaelc@cs.wisc.edu>,
Jens Axboe <axboe@kernel.dk>, Chanho Min <chanho.min@lge.com>,
Hannes Reinecke <hare@suse.de>
Subject: Re: [PATCH v6 03/13] block: Avoid that request_fn is invoked on a dead queue
Date: Sun, 02 Dec 2012 14:35:52 +0100 [thread overview]
Message-ID: <50BB5938.9040207@acm.org> (raw)
In-Reply-To: <20121202132320.GC15930@mtj.dyndns.org>
On 12/02/12 14:23, Tejun Heo wrote:
> On Wed, Nov 28, 2012 at 01:44:53PM +0100, Bart Van Assche wrote:
>> A block driver may start cleaning up resources needed by its
>> request_fn as soon as blk_cleanup_queue() finished, so request_fn
>> must not be invoked after draining finished. This is important
>> when blk_run_queue() is invoked without any requests in progress.
>> As an example, if blk_drain_queue() and scsi_run_queue() run in
>> parallel, blk_drain_queue() may have finished all requests after
>> scsi_run_queue() has taken a SCSI device off the starved list but
>> before that last function has had a chance to run the queue.
>>
>> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
>> Cc: James Bottomley <JBottomley@Parallels.com>
>> Cc: Mike Christie <michaelc@cs.wisc.edu>
>> Cc: Jens Axboe <axboe@kernel.dk>
>> Cc: Tejun Heo <tj@kernel.org>
>> Cc: Chanho Min <chanho.min@lge.com>
>
> Acked-by: Tejun Heo <tj@kernel.org>
>
>> +inline void __blk_run_queue_uncond(struct request_queue *q)
>
> Does this inline actually make a difference in the generated code?
Yes. Without that "inline" keyword that function is not inlined in
__blk_run_queue() but with that "inline" keyword it is inlined. At least
with gcc 4.7.1 - I have not checked any other gcc versions.
Bart.
next prev parent reply other threads:[~2012-12-02 13:35 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-28 12:39 [PATCH 0/13 v6] More device removal fixes Bart Van Assche
2012-11-28 12:42 ` [PATCH v6 01/13] block: Rename queue dead flag Bart Van Assche
2012-11-28 12:43 ` [PATCH v6 02/13] block: Let blk_drain_queue() caller obtain the queue lock Bart Van Assche
2012-11-28 12:44 ` [PATCH v6 03/13] block: Avoid that request_fn is invoked on a dead queue Bart Van Assche
2012-12-02 13:23 ` Tejun Heo
2012-12-02 13:35 ` Bart Van Assche [this message]
2012-11-28 12:45 ` [PATCH v6 04/13] block: Avoid scheduling delayed work " Bart Van Assche
2012-12-02 13:26 ` Tejun Heo
2012-12-02 13:41 ` Bart Van Assche
2012-12-02 13:59 ` Tejun Heo
2012-11-28 12:46 ` [PATCH v6 05/13] block: Make blk_cleanup_queue() wait until request_fn finished Bart Van Assche
2012-12-02 13:28 ` Tejun Heo
2012-11-28 12:47 ` [PATCH v6 06/13] bsg: Remove unused function bsg_goose_queue() Bart Van Assche
2012-12-02 13:29 ` Tejun Heo
2012-11-28 12:48 ` [PATCH v6 07/13] Fix race between starved list processing and device removal Bart Van Assche
2012-12-02 13:32 ` Tejun Heo
2012-11-28 12:48 ` [PATCH v6 08/13] Remove get_device() / put_device() pair from scsi_request_fn() Bart Van Assche
2012-12-02 13:34 ` Tejun Heo
2012-11-28 12:50 ` [PATCH v6 09/13] Avoid saving/restoring interrupt state inside scsi_remove_host() Bart Van Assche
2012-12-02 13:35 ` Tejun Heo
2012-11-28 12:51 ` [PATCH v6 10/13] Make scsi_remove_host() wait for device removal Bart Van Assche
2012-12-02 13:45 ` Tejun Heo
2012-12-02 13:48 ` Tejun Heo
2012-12-03 8:23 ` Bart Van Assche
2012-12-03 16:15 ` Tejun Heo
2012-12-03 16:38 ` Bart Van Assche
2012-12-03 16:42 ` Tejun Heo
2012-12-07 7:41 ` Bart Van Assche
2012-11-28 12:52 ` [PATCH v6 11/13] Make scsi_remove_host() wait until error handling finished Bart Van Assche
2012-12-02 13:51 ` Tejun Heo
2012-11-28 12:53 ` [PATCH v6 12/13] Avoid that scsi_device_set_state() triggers a race Bart Van Assche
2012-12-02 13:53 ` Tejun Heo
2012-11-28 12:53 ` [PATCH v6 13/13] Do not queue new I/O after scsi_remove_host() started Bart Van Assche
2012-12-02 13:58 ` Tejun Heo
2012-12-02 14:02 ` [PATCH 0/13 v6] More device removal fixes Tejun Heo
2012-12-06 13:33 ` Jens Axboe
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