df4684: fence=0xfffff8008f90ce80 refcount=1 (array ref only M-bM^@M^T the steady state of a completed, unprocessed fence)
df4684: reader :306 rcu_dereference(slot) = 0xfffff8008f90ce80
df4684: *** fence IRQ fires NOW, preempting the reader ***
df4684: writer :258 dma_fence_signal -> 0
df4684: release #1: refcount hit 0 -> call_rcu(&f->rcu=0xfffff8008f90ce98, free)
drm: expand RCU cpu 2 to 16
df4684: reader :307 dma_fence_get_rcu(0xfffff8008f90ce80) = 0, refcount resurrected to 0
df4684: get_rcu refused the dead fence (FIXED header) -> wait_empty returns 0, no put
df4684: [delay-line fired #1] amdgpu_fence_free equivalent: kmem_cache_free(0xfffff8008f90ce80)