Re: kern/58666: panic: lock error: Reader / writer lock: rw_vector_enter,357: locking against myself

[Taylor R Campbell <riastradh%NetBSD.org@localhost>]

> Date: Sun, 8 Sep 2024 12:04:36 +0000
> From: Taylor R Campbell <riastradh%NetBSD.org@localhost>
> 
> 5. RAM is currently short so uvm_km_alloc would have to sleep and wait
>    for the pagedaemon to free pages before it can return, in which
>    case it returns null instead of sleeping because pmap_pdp_alloc
>    didn't pass UVM_KMF_WAITVA.

Correction: kernel virtual address space, not RAM, is short, so
uvm_km_alloc would have to sleep and wait for the pagedaemon to find
some kva pages to free.  By passing UVM_KMF_WAITVA, pmap_pdp_alloc
would wait for kva instead of returning null.