On Mon, 3 Mar 2025 11:47:11 -0500 Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > > [ 92.322619][ T28] ? srcu_gp_start_if_needed+0x1a9/0x5f0 > > [ 92.322636][ T28] srcu_gp_start_if_needed+0x1a9/0x5f0 > > The lock taken is from the passed in rcu_pending pointer. > > > [ 92.322655][ T28] rcu_pending_enqueue+0x686/0xd30 I figured out what likely triggered the lockdep warning too. I thought rcu_pending_equeue() was an internal RCU function, but then when I looked at what directory it was in (found it in emacs so I only saw the file name and not the path), I see that function is internal to bcachefs. That function also has: local_irq_save(flags); p = this_cpu_ptr(pending->p); spin_lock(&p->lock); That is a sure sign of an RT disaster waiting to happen. As in PREEMPT_RT that spin_lock turns into a mutex, and just before, you disable interrupts. And yes, lockdep will report that as a bug. -- Steve
