target: Convert se_device statistics to atomic_long_t
This patch converts the handful of se_device statistics to type
atomic_long_t, instead of using se_device->stats_lock when
incrementing these values.
More importantly, go ahead and drop the spinlock usage within
transport_lookup_cmd_lun() fast-path code.
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index dbe40ef..986afd2 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -130,15 +130,12 @@
/* Directly associate cmd with se_dev */
se_cmd->se_dev = se_lun->lun_se_dev;
- /* TODO: get rid of this and use atomics for stats */
dev = se_lun->lun_se_dev;
- spin_lock_irqsave(&dev->stats_lock, flags);
- dev->num_cmds++;
+ atomic_long_inc(&dev->num_cmds);
if (se_cmd->data_direction == DMA_TO_DEVICE)
- dev->write_bytes += se_cmd->data_length;
+ atomic_long_add(se_cmd->data_length, &dev->write_bytes);
else if (se_cmd->data_direction == DMA_FROM_DEVICE)
- dev->read_bytes += se_cmd->data_length;
- spin_unlock_irqrestore(&dev->stats_lock, flags);
+ atomic_long_add(se_cmd->data_length, &dev->read_bytes);
return 0;
}
@@ -1426,7 +1423,6 @@
INIT_LIST_HEAD(&dev->state_list);
INIT_LIST_HEAD(&dev->qf_cmd_list);
INIT_LIST_HEAD(&dev->g_dev_node);
- spin_lock_init(&dev->stats_lock);
spin_lock_init(&dev->execute_task_lock);
spin_lock_init(&dev->delayed_cmd_lock);
spin_lock_init(&dev->dev_reservation_lock);