From: Christoph Hellwig <hch@lst.de>
To: Kashyap Desai <kashyap.desai@avagotech.com>
Cc: Christoph Hellwig <hch@lst.de>,
James Bottomley <James.Bottomley@hansenpartnership.com>,
linux-scsi@vger.kernel.org, Jens Axboe <axboe@kernel.dk>,
Bart Van Assche <bvanassche@fusionio.com>,
Mike Christie <michaelc@cs.wisc.edu>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
Robert Elliott <Elliott@hp.com>, Webb Scales <webbnh@hp.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 13/14] scsi: add support for a blk-mq based I/O path.
Date: Tue, 19 Aug 2014 18:06:25 +0200 [thread overview]
Message-ID: <20140819160625.GA29770@lst.de> (raw)
In-Reply-To: <885d029677826efe0cfe3803411cbdba@mail.gmail.com>
On Tue, Aug 19, 2014 at 03:51:42AM +0530, Kashyap Desai wrote:
> I read this comment and find that very few drivers are using this
> cmd_list. I think if we remove this cmd_list, performance will scale as I
> am seeing major contention in this lock.
> Just thought to ping you to see if this is known limitation for now or any
> plan to change this lock in near future ?
Removing the lock entirely and pushing the list into the two drivers
using it is on my TODO list. Bart actually suggested keeping the code in the
SCSI core and having a flag to enabled. Given that I'm too busy to get my full
version done in time, it might be a good idea if someone picks up Barts
idea. Can you send me a patch to add a enable_cmd_list flag to the host
template and only enable it for aacraid and dpt_i2o?
next prev parent reply other threads:[~2014-08-19 16:06 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-18 10:12 scsi-mq V4 Christoph Hellwig
2014-07-18 10:13 ` [PATCH 01/14] scsi: add scsi_setup_cmnd helper Christoph Hellwig
2014-07-22 3:42 ` Martin K. Petersen
2014-07-22 17:20 ` Webb Scales
2014-07-18 10:13 ` [PATCH 02/14] scsi: split __scsi_queue_insert Christoph Hellwig
2014-07-22 3:44 ` Martin K. Petersen
2014-07-18 10:13 ` [PATCH 03/14] scsi: centralize command re-queueing in scsi_dispatch_fn Christoph Hellwig
2014-07-22 3:46 ` Martin K. Petersen
2014-07-18 10:13 ` [PATCH 04/14] scsi: set ->scsi_done before calling scsi_dispatch_cmd Christoph Hellwig
2014-07-22 3:48 ` Martin K. Petersen
2014-07-18 10:13 ` [PATCH 05/14] scsi: push host_lock down into scsi_{host,target}_queue_ready Christoph Hellwig
2014-07-22 3:52 ` Martin K. Petersen
2014-07-18 10:13 ` [PATCH 06/14] scsi: convert target_busy to an atomic_t Christoph Hellwig
2014-07-22 3:56 ` Martin K. Petersen
2014-07-18 10:13 ` [PATCH 07/14] scsi: convert host_busy to atomic_t Christoph Hellwig
2014-07-22 4:01 ` Martin K. Petersen
2014-07-22 4:18 ` Martin K. Petersen
2014-07-25 11:38 ` Christoph Hellwig
2014-07-18 10:13 ` [PATCH 08/14] scsi: convert device_busy " Christoph Hellwig
2014-07-18 10:13 ` [PATCH 09/14] scsi: fix the {host,target,device}_blocked counter mess Christoph Hellwig
2014-07-25 19:08 ` Martin K. Petersen
2014-07-18 10:13 ` [PATCH 10/14] scsi: only maintain target_blocked if the driver has a target queue limit Christoph Hellwig
2014-07-25 19:10 ` Martin K. Petersen
2014-07-18 10:13 ` [PATCH 11/14] scsi: unwind blk_end_request_all and blk_end_request_err calls Christoph Hellwig
2014-07-25 19:12 ` Martin K. Petersen
2014-07-18 10:13 ` [PATCH 12/14] scatterlist: allow chaining to preallocated chunks Christoph Hellwig
2014-07-25 19:15 ` Martin K. Petersen
2014-07-18 10:13 ` [PATCH 13/14] scsi: add support for a blk-mq based I/O path Christoph Hellwig
2014-07-25 19:29 ` Martin K. Petersen
2014-08-18 22:21 ` Kashyap Desai
2014-08-19 15:41 ` Kashyap Desai
2014-08-19 16:06 ` Christoph Hellwig [this message]
2014-08-19 16:11 ` Kashyap Desai
2014-07-18 10:13 ` [PATCH 14/14] fnic: reject device resets without assigned tags for the blk-mq case Christoph Hellwig
2014-07-25 19:31 ` Martin K. Petersen
-- strict thread matches above, loose matches on Subject: below --
2014-06-25 16:51 scsi-mq V2 Christoph Hellwig
2014-06-25 16:52 ` [PATCH 13/14] scsi: add support for a blk-mq based I/O path Christoph Hellwig
2014-07-09 11:25 ` Hannes Reinecke
2014-07-16 11:13 ` Mike Christie
2014-07-16 11:16 ` Christoph Hellwig
2014-06-12 13:48 scsi-mq Christoph Hellwig
2014-06-12 13:49 ` [PATCH 13/14] scsi: add support for a blk-mq based I/O path Christoph Hellwig
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