On Sun, Jun 30, 2019 at 12:40:54AM +0000, Jason Gunthorpe wrote:

On Tue, Jun 18, 2019 at 08:26:14PM +0300, Leon Romanovsky wrote:

quoted

+static void __rdma_counter_dealloc(struct rdma_counter *counter)
+{
+	mutex_lock(&counter->lock);
+	counter->device->ops.counter_dealloc(counter);
+	mutex_unlock(&counter->lock);
+}

Does this lock do anything? The kref is 0 at this point, so no other
thread can have a pointer to this lock.

Yes, it is leftover from atomic_read implementation.

quoted

+
+static void rdma_counter_dealloc(struct rdma_counter *counter)
+{
+	if (!counter)
+		return;

Counter is never NULL.

Ohh, right, I'll clean some code near rdma_counter_dealloc/__rdma_counter_dealloc.

Thanks

Jason