Re: ATF tests panic assertion "uvmexp.swpgonly > 0" failed

[Chuck Silvers <chuq%chuq.com@localhost>]

On Fri, Dec 08, 2023 at 06:13:42PM +0100, Manuel Bouyer wrote:
> Hello again
> I see a second rare panic running ATF tests on Xen:
> lib/libc/regex/t_exhaust (236/949): 1 test cases
>     regcomp_too_big: [ 1254.5816543] panic: kernel diagnostic assertion "uvmexp.swpgonly > 0" failed: file "/usr/src/sys/uvm/uvm_anon.c", line 175 
> [ 1254.6116351] cpu1: Begin traceback...
> [ 1254.6216378] vpanic(c12d3bf8,d855adcc,d855ade8,c0d03f72,c12d3bf8,c12d3b5f,c13da23e,c13da189,af,c3b00ac0) at netbsd:vpanic+0x184
> [ 1254.6516393] kern_assert(c12d3bf8,c12d3b5f,c13da23e,c13da189,af,c3b00ac0,c2d9f8d0,0,d855ae0c,c0d041c4) at netbsd:kern_assert+0x23
> [ 1254.6716402] uvm_anfree(c2d9f8d0,c2342000,3,c543b0c0,0,c3b00ac0,1,d855ae58,c0d20d1d,c2d9f8d0) at netbsd:uvm_anfree+0x2b8
> [ 1254.7016358] uvm_anon_release(c2d9f8d0,1,d72f2000,c543b0c0,d72f2000,d72f1000,1,0,0,d855ae84) at netbsd:uvm_anon_release+0x85
> [ 1254.7216389] uvm_aio_aiodone_pages(d855ae84,1,1,0,c243c400,1ebf140,0,0,d855ae84,c1e6cc24) at netbsd:uvm_aio_aiodone_pages+0x2fc
> [ 1254.7716201] uvm_aio_aiodone(c5560180,8e016,3,0,72bec,c26ff204,c26ff204,c5560180,d855af20,c0e54a31) at netbsd:uvm_aio_aiodone+0x97
> [ 1254.7916387] biodone2(c5560180,1000,0,c25e4cec,c0db8d85,c5561024,c0e54996,d82f8000,d855af48,c0e0a32d) at netbsd:biodone2+0x95
> [ 1254.8216356] dkiodone(c5561024,10,10,d85502ac,c010293f,d855af70,c5561024,3,d855af70,c0e0a49e) at netbsd:dkiodone+0x9b
> [ 1254.8416368] biodone2(3,0,c010293f,8a260008,2,d8550004,c243c980,d85502ac,d855afe0,c0d7f5c5) at netbsd:biodone2+0x95
> [ 1254.8815946] biointr(0,0,0,0,0,0,0,0,0,0) at netbsd:biointr+0x4c
> [ 1254.8916211] softint_dispatch(c243c400,3,c2c2c2c2,c2c2c2c2,c2c2c2c2,c2c2c2c2,d855dff0,d855df14,c268b000,80050033) at netbsd:softint_dispatch+0xe0
> [ 1254.9216366] Bad frame pointer: 0xd82fcf20
> [ 1254.9316199] cpu1: End traceback...
> 
> The first time seems to be
> https://largo.lip6.fr/~bouyer/NetBSD-tests/xen/HEAD/i386-hvm/202310061820Z_anita.txt
> 
> and the second time was
> https://largo.lip6.fr/~bouyer/NetBSD-tests/xen/HEAD/i386-hvm/202311250810Z_anita.txt
> 
> Has anyone else seen this ?


yes, various people have been seeing this assertion (or some other related ones)
occasionally for years now.  I've looked into it a few times but I have been
unable to spot the problem.

-Chuck