NVMe: Set TASK_INTERRUPTIBLE before processing queues

The kthread has two tasks; handling timeouts (for which it runs once per
second), and submitting queued BIOs.  If a BIO happens to be queued after
the thread has processed the queue but before it calls schedule_timeout(),
the thread will sleep for a second before submitting it, which can cause
performance problems in some rare cases (that will become more common in
a subsequent patch).

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Tested-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
index 40908a06bd5e..358d17700c20 100644
--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -1291,7 +1291,7 @@ static int nvme_kthread(void *data)
         struct nvme_dev *dev;
 
         while (!kthread_should_stop()) {
-                __set_current_state(TASK_RUNNING);
+                set_current_state(TASK_INTERRUPTIBLE);
                 spin_lock(&dev_list_lock);
                 list_for_each_entry(dev, &dev_list, node) {
                         int i;
@@ -1308,7 +1308,6 @@ static int nvme_kthread(void *data)
                         }
                 }
                 spin_unlock(&dev_list_lock);
-                set_current_state(TASK_INTERRUPTIBLE);
                 schedule_timeout(round_jiffies_relative(HZ));
         }
         return 0;