On Thu Feb 5, 2026 at 2:48 PM CET, Matthew Wilcox wrote: > On Thu, Feb 05, 2026 at 01:44:27PM +0000, Gary Guo wrote: >> > Fix this by using an atomic counter to generate unique IDs for each >> > GPU's aux device registration. The TODO item to eventually use XArray >> > for recycling aux device IDs is retained, but for now, this works very >> > nicely. >> > >> > This has the side effect of making debugfs[1] work on multi-GPU systems. >> >> Hi John, >> >> Looks like this is something that should be achieved via IDA? > > Yes, if you have no need to go from ID to pointer, an IDA is better. > That said, as far as I understand what this code is doing, an atomic_t > solves the problem just fine and is cheaper.
I agree, for now an atomic should be perfectly fine. Though, with enough patience binding/unbinding the driver from sysfs you can probably make this overflow. :) The reason for the Xarray TODO is that it is one option for a place where nova-core can store nova-drm / vGPU specific data, once either vGPU or nova-drm attaches to the auxiliary device. But I think there may be better alternatives.
