Re: kern/43247 (KASSERT while copying 32GB file from NFS to TMPFS)

[Patrick Welche <prlw1%cam.ac.uk@localhost>]

The following reply was made to PR kern/43247; it has been noted by GNATS.

From: Patrick Welche <prlw1%cam.ac.uk@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: kern/43247 (KASSERT while copying 32GB file from NFS to TMPFS)
Date: Fri, 2 Oct 2020 11:06:53 +0100

 I just hit a panic with a very similar stack trace with 29 Sep 2020
 NetBSD-9.99.73/amd64:
 
 # crash -N netbsd.0 -M netbsd.0.core 
 Crash version 9.99.73, image version 9.99.73.
 crash: _kvm_kvatop(0)
 Kernel compiled without options LOCKDEBUG.
 System panicked: kernel diagnostic assertion "uvm_pagelookup(&aobj->u_obj, (UAO_SWHASH_ELT_PAGEIDX_BASE(elt) + j) << PAGE_SHIFT) == NULL" failed: file "../../../../uvm/uvm_aobj.c", line 1353 
 Backtrace from time of crash is available.
 crash> bt
 _KERNEL_OPT_NAGR() at 0
 _KERNEL_OPT_ACPI_SCANPCI() at _KERNEL_OPT_ACPI_SCANPCI+0xb
 sys_reboot() at sys_reboot
 vpanic() at vpanic+0x160
 __x86_indirect_thunk_rax() at __x86_indirect_thunk_rax
 uao_dropswap_range() at uao_dropswap_range+0x244
 tmpfs_reg_resize() at tmpfs_reg_resize+0x196
 tmpfs_inactive() at tmpfs_inactive+0x8e
 VOP_INACTIVE() at VOP_INACTIVE+0x3c
 vrelel() at vrelel+0x146
 tmpfs_remove() at tmpfs_remove+0x1ba
 VOP_REMOVE() at VOP_REMOVE+0x40
 do_sys_unlinkat() at do_sys_unlinkat+0x211
 syscall() at syscall+0xa1
 --- syscall (number 10) ---
 
 The box has 32GB ram + 2x32=64GB swap. It had been several builds, so
 tmpfs /tmp was quite full. The panic happened on shutdown. shutdown
 was stuck in "swapctl -U -t blk". swapctl -lh, and  top hung. 
 rm /tmp/obj "caused" the panic.