[PATCH] s390: Initialize nr_devices count variable to -1

From: Aniroop Mathur
Date: Sun Dec 28 2014 - 11:13:01 EST


From: Aniroop Mathur <a.mathur@xxxxxxxxxxx>

This patch initializes nr_device count variable to -1 to avoid extra
subtraction operation performed everytime scm block device is set up.

Signed-off-by: Aniroop Mathur <a.mathur@xxxxxxxxxxx>
---
drivers/s390/block/scm_blk.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/s390/block/scm_blk.c b/drivers/s390/block/scm_blk.c
index 76bed17..ee2bd6f 100644
--- a/drivers/s390/block/scm_blk.c
+++ b/drivers/s390/block/scm_blk.c
@@ -23,7 +23,7 @@ static int scm_major;
static DEFINE_SPINLOCK(list_lock);
static LIST_HEAD(inactive_requests);
static unsigned int nr_requests = 64;
-static atomic_t nr_devices = ATOMIC_INIT(0);
+static atomic_t nr_devices = ATOMIC_INIT(-1);
module_param(nr_requests, uint, S_IRUGO);
MODULE_PARM_DESC(nr_requests, "Number of parallel requests.");

@@ -357,7 +357,7 @@ int scm_blk_dev_setup(struct scm_blk_dev *bdev, struct scm_device *scmdev)
int len, ret = -ENOMEM;
unsigned int devindex, nr_max_blk;

- devindex = atomic_inc_return(&nr_devices) - 1;
+ devindex = atomic_inc_return(&nr_devices);
/* scma..scmz + scmaa..scmzz */
if (devindex > 701) {
ret = -ENODEV;
--
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/