kern/54188: uvm/pmap panic

[prlw1%cam.ac.uk@localhost]

>Number:         54188
>Category:       kern
>Synopsis:       uvm/pmap panic
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri May 10 08:55:00 +0000 2019
>Originator:     Patrick Welche
>Release:        NetBSD-8.99.39/amd64
>Organization:
>Environment:
>Description:
Updated a box to yesterday's current, and came in to find that it had an uptime of 6 hours. All I have to go on is the following from /var/log/messages, and the timing suggesting that the panic happened during a run of "daily".

[ 47842.168328] panic: pmap_get_physpage: out of memory
[ 47842.168328] cpu0: Begin traceback...
[ 47842.168328] vpanic() at netbsd:vpanic+0x143
[ 47842.168328] snprintf() at netbsd:snprintf
[ 47842.168328] pmap_growkernel() at netbsd:pmap_growkernel
[ 47842.168328] pmap_growkernel() at netbsd:pmap_growkernel+0x18c
[ 47842.168328] uvm_map_prepare() at netbsd:uvm_map_prepare+0x24f
[ 47842.168328] uvm_map() at netbsd:uvm_map+0x39
[ 47842.168328] uvm_km_alloc() at netbsd:uvm_km_alloc+0x8a
[ 47842.168328] pool_grow() at netbsd:pool_grow+0x7c
[ 47842.168328] pool_catchup() at netbsd:pool_catchup+0x23
[ 47842.168328] pool_get() at netbsd:pool_get+0x2d4
[ 47842.168328] allocbuf() at netbsd:allocbuf+0xe4
[ 47842.168328] getblk() at netbsd:getblk+0x13f
[ 47842.168328] bio_doread() at netbsd:bio_doread+0x1d
[ 47842.168328] bread() at netbsd:bread+0x18
[ 47842.168328] ffs_init_vnode() at netbsd:ffs_init_vnode+0x9d
[ 47842.168328] ffs_loadvnode() at netbsd:ffs_loadvnode+0x43
[ 47842.168328] vcache_get() at netbsd:vcache_get+0x1d6
[ 47842.168328] ufs_lookup() at netbsd:ufs_lookup+0x9be
[ 47842.168328] VOP_LOOKUP() at netbsd:VOP_LOOKUP+0x34
[ 47842.168328] lookup_once() at netbsd:lookup_once+0x18b
[ 47842.168328] namei_tryemulroot() at netbsd:namei_tryemulroot+0x31c
[ 47842.178332] namei() at netbsd:namei+0x41
[ 47842.178332] fd_nameiat.isra.2() at netbsd:fd_nameiat.isra.2+0x54
[ 47842.178332] do_sys_statat() at netbsd:do_sys_statat+0x77
[ 47842.178332] sys___lstat50() at netbsd:sys___lstat50+0x25
[ 47842.178332] syscall() at netbsd:syscall+0x13f
[ 47842.178332] --- syscall (number 441) ---
[ 47842.178332] 748db198f10a:
[ 47842.178332] cpu0: End traceback...

It is possible that it was also compiling rust or somesuch with a tmpfs WRKDIR so ran out of swap that way?
>How-To-Repeat:

>Fix: