On Sat, 26 Sep 2026 23:24:52 +0700 Nguyen Ngoc Thang wrote:
> virtio_gpu_alloc_vbufs() creates a kmem_cache with the fixed name
> "virtio-gpu-vbufs" for every device and destroys it from
> virtio_gpu_release(), which only runs once the last drm_device
> reference is dropped. If a reference outlives the PCI removal (for
> instance an open /dev/fbN), a rescan probes the device again while the
> old cache still exists:
>
> kmem_cache of name 'virtio-gpu-vbufs' already exists
> WARNING: mm/slab_common.c:111 at __kmem_cache_create_args
> Call Trace:
> virtio_gpu_alloc_vbufs
> virtio_gpu_init
> virtio_gpu_probe
> ...
> pci_rescan_bus
> rescan_store
>
> kmem_cache_create() then fails and the new device does not probe.
>
> The vbuf size is the same for every device, so create the cache once
> at module init and destroy it at module exit instead of per device.
>
What is unclear -- why is kmalloc failing to work in 2026?
