> -----Original Message----- > From: Christoph Hellwig [mailto:hch@xxxxxx] > Sent: Thursday, 12 June, 2014 8:49 AM > To: James Bottomley > Cc: Jens Axboe; Bart Van Assche; Elliott, Robert (Server Storage); linux- > scsi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx > Subject: [PATCH 10/14] scsi: only maintain target_blocked if the driver has a > target queue limit > > This saves us an atomic operation for each I/O submission and completion > for the usual case where the driver doesn't set a per-target can_queue > value. Only a few iscsi hardware offload drivers set the per-target > can_queue value at the moment. > > Signed-off-by: Christoph Hellwig <hch@xxxxxx> > --- > drivers/scsi/scsi_lib.c | 17 ++++++++++++----- > 1 file changed, 12 insertions(+), 5 deletions(-) > > diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c > index 0e33dee..763b3c9 100644 > --- a/drivers/scsi/scsi_lib.c > +++ b/drivers/scsi/scsi_lib.c ... > @@ -1642,7 +1648,8 @@ static void scsi_request_fn(struct request_queue *q) > return; > > host_not_ready: > - atomic_dec(&scsi_target(sdev)->target_busy); > + if (&scsi_target(sdev)->can_queue > 0) > + atomic_dec(&scsi_target(sdev)->target_busy); > not_ready: > /* > * lock q, handle tag, requeue req, and decrement device_busy. We There's an extra & in that if statement. --- Rob Elliott HP Server Storage -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
