From: Christoph Hellwig <hch@infradead.org>
To: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Bart Van Assche <bvanassche@acm.org>, Hannes Reinecke <hare@suse.de>
Subject: [PATCH 11/39] scsi: remove a useless get/put_device pair in scsi_next_command
Date: Mon, 17 Mar 2014 06:27:44 -0700 [thread overview]
Message-ID: <20140317133133.123581521@bombadil.infradead.org> (raw)
In-Reply-To: 20140317132733.789623766@bombadil.infradead.org
[-- Attachment #1: 0011-scsi-remove-a-useless-get-put_device-pair-in-scsi_ne.patch --]
[-- Type: text/plain, Size: 1005 bytes --]
Eliminate a get_device() / put_device() pair from scsi_next_command().
Both are atomic operations hence removing these slightly improves
performance.
[hch: slight changes due to different context]
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/scsi/scsi_lib.c | 5 -----
1 file changed, 5 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index a6d5525..6866943 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -526,14 +526,9 @@ void scsi_next_command(struct scsi_cmnd *cmd)
struct scsi_device *sdev = cmd->device;
struct request_queue *q = sdev->request_queue;
- /* need to hold a reference on the device before we let go of the cmd */
- get_device(&sdev->sdev_gendev);
-
scsi_put_command(cmd);
- put_device(&sdev->sdev_gendev);
scsi_run_queue(q);
- /* ok to remove device now */
put_device(&sdev->sdev_gendev);
}
--
1.7.10.4
next prev parent reply other threads:[~2014-03-17 13:45 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-17 13:27 [PATCH 00/39] [WIP] scsi multiqueue Christoph Hellwig
2014-03-17 13:27 ` [PATCH 01/39] block: fix q->flush_rq NULL pointer crash on dm-mpath flush Christoph Hellwig
2014-03-17 13:27 ` [PATCH 02/39] block: change flush sequence list addition back to front add Christoph Hellwig
2014-03-17 13:27 ` [PATCH 03/39] blk-mq: fix blk_mq_end_io_partial Christoph Hellwig
2014-03-17 13:27 ` [PATCH 04/39] blk-mq: initialize resid_len Christoph Hellwig
2014-03-17 13:27 ` [PATCH 05/39] blk-mq: replace blk_mq_init_commands with a ->init_request method Christoph Hellwig
2014-03-17 13:27 ` [PATCH 06/39] blk-mq: add a exit_request method Christoph Hellwig
2014-03-17 13:27 ` [PATCH 07/39] scsi: avoid useless free_list lock roundtrips Christoph Hellwig
2014-03-17 13:27 ` [PATCH 08/39] scsi: avoid taking host_lock in scsi_run_queue unless nessecary Christoph Hellwig
2014-03-17 13:27 ` [PATCH 09/39] scsi: do not manipulate device reference counts in scsi_get/put_command Christoph Hellwig
2014-03-17 13:27 ` [PATCH 10/39] scsi: remove a useless get/put_device pair in scsi_request_fn Christoph Hellwig
2014-03-17 13:27 ` Christoph Hellwig [this message]
2014-03-17 13:27 ` [PATCH 12/39] scsi: remove a useless get/put_device pair in scsi_requeue_command Christoph Hellwig
2014-03-17 13:27 ` [PATCH 13/39] megaraid: simplify internal command handling Christoph Hellwig
2014-03-21 1:12 ` adam radford
2014-03-17 13:27 ` [PATCH 14/39] scsi: simplify command allocation and freeing a bit Christoph Hellwig
2014-03-17 13:27 ` [PATCH 15/39] scsi: add support for per-host cmd pools Christoph Hellwig
2014-03-17 13:27 ` [PATCH 16/39] virtio_scsi: use cmd_size Christoph Hellwig
2014-03-25 15:31 ` Christoph Hellwig
2014-03-25 15:36 ` Paolo Bonzini
2014-03-27 15:28 ` James Bottomley
2014-03-17 13:27 ` [PATCH 17/39] scsi: explicitly release bidi buffers Christoph Hellwig
2014-03-17 13:27 ` [PATCH 18/39] scsi: remove scsi_end_request Christoph Hellwig
2014-03-17 13:27 ` [PATCH 19/39] scsi: push host_lock down into scsi_{host,target}_queue_ready Christoph Hellwig
2014-03-17 13:27 ` [PATCH 20/39] scsi: convert target_busy to an atomic_t Christoph Hellwig
2014-03-17 13:27 ` [PATCH 21/39] scsi: convert host_busy to atomic_t Christoph Hellwig
2014-03-17 13:27 ` [PATCH 22/39] scsi: convert device_busy " Christoph Hellwig
2014-03-17 13:27 ` [PATCH 23/39] scsi: fix the {host,target,device}_blocked counter mess Christoph Hellwig
2014-03-17 13:27 ` [PATCH 24/39] blk-mq: add blk_mq_requeue_request Christoph Hellwig
2014-03-17 13:27 ` [PATCH 25/39] blk-mq: add async paramter to blk_mq_start_stopped_hw_queues Christoph Hellwig
2014-03-17 13:27 ` [PATCH 26/39] HACK: support blk_delay_queue for blk-mq Christoph Hellwig
2014-03-17 13:28 ` [PATCH 27/39] blk-mq: export blk_mq_insert_request Christoph Hellwig
2014-03-17 13:28 ` [PATCH 28/39] scsi: reintroduce scsi_driver.init_command Christoph Hellwig
2014-03-26 9:46 ` Christoph Hellwig
2014-03-17 13:28 ` [PATCH 29/39] block: remove unprep_rq_fn Christoph Hellwig
2014-03-17 13:28 ` [PATCH 30/39] scsi: centralize command re-queueing in scsi_dispatch_fn Christoph Hellwig
2014-03-17 13:28 ` [PATCH 31/39] scsi: split __scsi_queue_insert Christoph Hellwig
2014-03-17 13:28 ` [PATCH 32/39] scsi: unwind blk_end_request_all and blk_end_request_err calls Christoph Hellwig
2014-03-17 13:28 ` [PATCH 33/39] scsi: initial blk-mq support Christoph Hellwig
2014-03-17 13:28 ` [PATCH 34/39] scsi: partially stub out scsi_adjust_queue_depth when using blk-mq Christoph Hellwig
2014-03-17 13:28 ` [PATCH 35/39] virtio_scsi: use blk_mq Christoph Hellwig
2014-03-17 13:28 ` [PATCH 36/39] iscsi_tcp: " Christoph Hellwig
2014-03-17 13:28 ` [PATCH 37/39] ata_piix: " Christoph Hellwig
2014-03-17 13:28 ` [PATCH 38/39] blk-mq: make blk_mq_start_stopped_hw_queues run a queue even if not stopped Christoph Hellwig
2014-03-17 13:28 ` [PATCH 39/39] scsi: implement ->init_request and ->exit_request Christoph Hellwig
2014-03-17 13:33 ` [PATCH 00/39] [WIP] scsi multiqueue Christoph Hellwig
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