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| author | Christoph Hellwig <hch@lst.de> | 2014-01-22 18:29:29 +0400 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2014-07-25 15:43:43 +0400 |
| commit | 74665016086615bbaa3fa6f83af410a0a4e029ee (patch) | |
| tree | 9f9d8a692bec91dce69fd303eeedf16c35b41ac6 /drivers/scsi/qlogicpti.c | |
| parent | 7ae65c0f9646c29432b69580b80e08632e6cd813 (diff) | |
| download | linux-74665016086615bbaa3fa6f83af410a0a4e029ee.tar.xz | |
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>
Diffstat (limited to 'drivers/scsi/qlogicpti.c')
| -rw-r--r-- | drivers/scsi/qlogicpti.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/scsi/qlogicpti.c b/drivers/scsi/qlogicpti.c index 6d48d30bed05..740ae495aa77 100644 --- a/drivers/scsi/qlogicpti.c +++ b/drivers/scsi/qlogicpti.c @@ -959,7 +959,7 @@ static inline void update_can_queue(struct Scsi_Host *host, u_int in_ptr, u_int /* Temporary workaround until bug is found and fixed (one bug has been found already, but fixing it makes things even worse) -jj */ int num_free = QLOGICPTI_REQ_QUEUE_LEN - REQ_QUEUE_DEPTH(in_ptr, out_ptr) - 64; - host->can_queue = host->host_busy + num_free; + host->can_queue = atomic_read(&host->host_busy) + num_free; host->sg_tablesize = QLOGICPTI_MAX_SG(num_free); } |