On 11/18/2018 9:29 AM, Leon Romanovsky wrote:
Hi, I want to clarify why IB device rename functionality didn't change debugfs and would like to ask what to do next. In drivers/infiniband/hw/*, we have 6 devices which are calling to debugfs_create_dir() in order to create debugfs root. The output is located in /sys/kernel/debug/. Such folders are created during driver module load and some of the drivers creates subfolders for every device initialized, during device probe. 1. PCI-based connection MLX5 and cxgb4 drivers separate the different device by their PCIs. [leonro@server ~]$ sudo ls /sys/kernel/debug/mlx5/ 0000:00:0c.0 2. Based on IB device name HFI1, ocrdma and qib create subfolders with device index embedded in it, like hfi1_0,...,hfi1_N 3. No-separation between devices USNIC like this. So device rename works seamlessly for type #1 and #3. Wile for type #2, the debugfs entries don't change. Right now, I see three options: 1. Do nothing. 2. Convert type #2 drivers to be type #1. 3. Add callback/extra implementation in IB/core to support one live driver (hfi1) and two frozen ones.
It's certainly not accurate to call qib frozen. We may not plan on any new features but we do intend to keep it live and provide fixes should the need arise.
I think the type #2 is much more user friendly than putting in the PCI-ID so why not convert type #1 to be type #2?
Now that being said I would imagine we could go with either approach and leave it up to the administrator to create a udev rule or something and make symlinks to keep existing tools compatible. So I don't think we need to support both. The question is which is better #1 or #2?
-Denny
