atomic_load_relaxed panic

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

On an otherwise idle amd64 box running

  NetBSD 9.99.81 (GENERIC) #3: Fri Mar 26 17:37:48 GMT 2021

I got tantalisingly close to managing to clone the NetBSD source:

# hg clone http://anonhg.netbsd.org/src
destination directory: src
applying clone bundle from https://cdn.NetBSD.org/_bundles/src/77d2a2ece3a06d837da45acd0fda80086ab4113c.zstd.hg
adding changesets
adding manifests                                                                                                                       
adding file changes                                                                                                                    
added 931876 changesets with 2425841 changes to 439702 files (+417 heads)                                                              
finished applying clone bundle
searching for changes
adding changesets
adding manifests
adding file changes
adding changesets
adding manifests
adding file changes
added 14681 changesets with 130115 changes to 91055 files (+5 heads)
new changesets 26c8f37631b6:87ca3e58cbb1 (241 drafts)
280333 local changesets published
updating to branch trunk
updating [=================>                           ]  71400/202610 17s

(any hints on making this go faster?)

When:

[ 257027.9185592] panic: kernel diagnostic assertion "atomic_load_relaxed(&pp-> 
[ 257027.9485598] cpu2: Begin traceback...                                      
[ 257027.9585600] vpanic() at netbsd:vpanic+0x156                               
[ 257027.9685597] __x86_indirect_thunk_rax() at netbsd:__x86_indirect_thunk_rax
[ 257027.9785609] pmap_clear_attrs() at netbsd:pmap_clear_attrs+0x124
[ 257027.9985632] uvm_pagemarkdirty() at netbsd:uvm_pagemarkdirty+0x37b
[ 257028.0085600] uao_get() at netbsd:uao_get+0x315
[ 257028.0185597] ubc_fault() at netbsd:ubc_fault+0x16a
[ 257028.0285614] uvm_fault_internal() at netbsd:uvm_fault_internal+0x57a
[ 257028.0485613] trap() at netbsd:trap+0x5b7
[ 257028.0485613] --- trap (number 6) ---
[ 257028.0585610] copyout() at netbsd:copyout+0x33
[ 257028.0685603] uiomove() at netbsd:uiomove+0x80
[ 257028.0785605] ubc_uiomove() at netbsd:ubc_uiomove+0x157
[ 257028.0885612] tmpfs_read() at netbsd:tmpfs_read+0xbe
[ 257028.0985609] VOP_READ() at netbsd:VOP_READ+0x40
[ 257028.1185598] vn_read() at netbsd:vn_read+0x97
[ 257028.1285595] dofileread() at netbsd:dofileread+0x79
[ 257028.1385631] sys_read() at netbsd:sys_read+0x49
[ 257028.1485614] syscall() at netbsd:syscall+0x23e
[ 257028.1585616] --- syscall (number 3) ---
[ 257028.1685608] netbsd:syscall+0x23e:
[ 257028.1685608] cpu2: End traceback...

[ 257028.1785615] dumping to dev 168,2 (offset=8, size=41938679):
[ 257028.1885651] dump 9684 9683 9682 9681 9680 9679 9678 9677 9676 9675 9674 9

tip in tmux doesn't appear to be wrapped... Hopefully the dump will succeed...


Cheers,

Patrick