[PATCH 5/9] scsi: remove a useless get/put_device pair in scsi_next_command

Christoph Hellwig
2014-02-20T22:23:58Z

[-- Attachment #1: 0005-scsi-remove-a-useless-get-put_device-pair-in-scsi_ne.patch --]
[-- Type: text/plain, Size: 1049 bytes --]

From: Bart Van Assche <bvanassche@acm.org>

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 7d35678..91ca414 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