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From: Christoph Hellwig <hch@lst.de>
To: "Elliott, Robert (Server Storage)" <Elliott@hp.com>
Cc: Bart Van Assche <bvanassche@acm.org>,
	Jens Axboe <axboe@kernel.dk>, Christoph Hellwig <hch@lst.de>,
	James Bottomley <James.Bottomley@HansenPartnership.com>,
	"linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: scsi-mq
Date: Mon, 23 Jun 2014 09:09:51 +0200	[thread overview]
Message-ID: <20140623070951.GB12267@lst.de> (raw)
In-Reply-To: <94D0CD8314A33A4D9D801C0FE68B402958B41923@G9W0745.americas.hpqcorp.net>

On Sat, Jun 21, 2014 at 12:52:22AM +0000, Elliott, Robert (Server Storage) wrote:
> Some of those context switches might be from scsi_end_request(), 
> which always schedules the scsi_requeue_run_queue() function via the
> requeue_work workqueue for scsi-mq.  That causes lots of context 
> switches from a busy application thread (e.g., fio) to a 
> kworker thread.

Jens has been prodding me to fix this up, I'll send a patch soon that avoids
the workqueue unless we need to kick other queues and thus walk the list
of LUNs.


  reply	other threads:[~2014-06-23  7:09 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-12 13:48 scsi-mq Christoph Hellwig
2014-06-12 13:48 ` [PATCH 01/14] sd: don't use rq->cmd_len before setting it up Christoph Hellwig
2014-06-12 13:48 ` [PATCH 02/14] scsi: split __scsi_queue_insert Christoph Hellwig
2014-06-12 13:48 ` [PATCH 03/14] scsi: centralize command re-queueing in scsi_dispatch_fn Christoph Hellwig
2014-06-12 13:48 ` [PATCH 04/14] scsi: set ->scsi_done before calling scsi_dispatch_cmd Christoph Hellwig
2014-06-12 13:48 ` [PATCH 05/14] scsi: push host_lock down into scsi_{host,target}_queue_ready Christoph Hellwig
2014-06-12 13:48 ` [PATCH 06/14] scsi: convert target_busy to an atomic_t Christoph Hellwig
2014-06-12 13:48 ` [PATCH 07/14] scsi: convert host_busy to atomic_t Christoph Hellwig
2014-06-12 13:49 ` [PATCH 08/14] scsi: convert device_busy " Christoph Hellwig
2014-06-12 13:49 ` [PATCH 09/14] scsi: fix the {host,target,device}_blocked counter mess Christoph Hellwig
2014-06-12 13:49 ` [PATCH 10/14] scsi: only maintain target_blocked if the driver has a target queue limit Christoph Hellwig
2014-06-21 22:10   ` Elliott, Robert (Server Storage)
2014-06-23  7:09     ` Christoph Hellwig
2014-06-12 13:49 ` [PATCH 11/14] scsi: unwind blk_end_request_all and blk_end_request_err calls Christoph Hellwig
2014-06-12 13:49 ` [PATCH 12/14] scatterlist: allow chaining to preallocated chunks Christoph Hellwig
2014-06-12 13:49 ` [PATCH 13/14] scsi: add support for a blk-mq based I/O path Christoph Hellwig
2014-06-12 13:49 ` [PATCH 14/14] fnic: reject device resets without assigned tags for the blk-mq case Christoph Hellwig
2014-06-13  6:42 ` scsi-mq Bart Van Assche
2014-06-17 14:27 ` scsi-mq Bart Van Assche
2014-06-18  3:44   ` scsi-mq Jens Axboe
2014-06-18  7:09     ` scsi-mq Bart Van Assche
2014-06-21  0:52       ` scsi-mq Elliott, Robert (Server Storage)
2014-06-23  7:09         ` Christoph Hellwig [this message]
2014-06-19  0:58     ` scsi-mq Elliott, Robert (Server Storage)

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