From: Christoph Hellwig <hch@lst.de>
Date: Wed, 22 Jan 2014 14:29:29 +0000 (+0100)
Subject: scsi: convert host_busy to atomic_t
X-Git-Tag: omap-for-v3.17/fixes-against-rc2~143^2~87
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=74665016086615bbaa3fa6f83af410a0a4e029ee;p=pandora-kernel.git

scsi: convert host_busy to atomic_t

Avoid taking the host-wide host_lock to check the per-host queue limit.
Instead we do an atomic_inc_return early on to grab our slot in the queue,
and if necessary decrement it after finishing all checks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Webb Scales <webbnh@hp.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Robert Elliott <elliott@hp.com>
---

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