From: Elias Oltmanns <eo@nebensachen.de>
To: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>,
       Jens Axboe <jens.axboe@oracle.com>
Cc: linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 7/7] ide: use queue lock instead of ide_lock when possible
Date: Fri, 10 Oct 2008 10:43:11 +0200
Message-ID: <87zllcet7k.fsf@denkblock.local>
References: <20081008202930.19112.90371.sendpatchset@localhost.localdomain>
	<20081008203027.19112.20883.sendpatchset@localhost.localdomain>
User-Agent: Gnus/5.110007 (No Gnus v0.7)
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1868
Lines: 49

Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> wrote:
> From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
> Subject: [PATCH] ide: use queue lock instead of ide_lock when possible
>
> This is just a preparation for future changes and there should be no
> functional changes caused by this patch since ide_lock is currently
> also used as queue lock.
>
> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
> ---
[...]
> Index: b/drivers/ide/ide-io.c
> ===================================================================
> --- a/drivers/ide/ide-io.c
> +++ b/drivers/ide/ide-io.c
[...]
> @@ -1469,16 +1470,16 @@ out:
>  void ide_do_drive_cmd(ide_drive_t *drive, struct request *rq)
>  {
>  	ide_hwgroup_t *hwgroup = drive->hwif->hwgroup;
> +	struct request_queue *q = drive->queue;
>  	unsigned long flags;
>  
>  	hwgroup->rq = NULL;
>  
> -	spin_lock_irqsave(&ide_lock, flags);
> -	__elv_add_request(drive->queue, rq, ELEVATOR_INSERT_FRONT, 1);
> -	__generic_unplug_device(drive->queue);
> -	spin_unlock_irqrestore(&ide_lock, flags);
> +	spin_lock_irqsave(q->queue_lock, flags);
> +	__elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 1);
> +	__generic_unplug_device(q);

By the way, wouldn't blk_run_queue() be more appropriate here? It looks
to me as if blk_run_queue() was the thing intended for general usage by
low level drivers who don't know and care about schedulers, whereas the
usage of __generic_unplug_device() should mostly be restricted to the
block layer. On the other hand, there are other drivers in
drivers/block/ that use __generic_unplug_device(), so I may well be
wrong. Jens?

Regards,

Elias
--
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/