Re: PR/46153 CVS commit: src/sys/kern

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Sat, Mar 10, 2012 at 08:50:04AM +0000, Martin Husemann wrote:
> The following reply was made to PR kern/46153; it has been noted by GNATS.
> 
> From: "Martin Husemann" <martin%netbsd.org@localhost>
> To: gnats-bugs%gnats.NetBSD.org@localhost
> Cc: 
> Subject: PR/46153 CVS commit: src/sys/kern
> Date: Sat, 10 Mar 2012 08:46:46 +0000
> 
>  Module Name: src
>  Committed By:        martin
>  Date:                Sat Mar 10 08:46:46 UTC 2012
>  
>  Modified Files:
>       src/sys/kern: kern_exec.c
>  
>  Log Message:
>  Make sure the child of a posix_spawn operation is not preempted during
>  the times when it does not have any vm_space.
>  Should fix PR kern/46153.

Unfortunably, with an up to date kernel:
     $NetBSD: kern_exec.c,v 1.345 2012/03/10 08:46:45 martin Exp $
I'm still seeing the problem:
Stopped in pid 25188.1 (t_fileactions) at       netbsd:pmap_deactivate+0x93:    
movq     0(%rax),%rbx
db{2}> sh reg
ds          2400
es          811e
fs          7ab0
gs          811e
rdi         fffffe8185b02800
rsi         0
rbp         fffffe810cc17b00
rbx         fffffe8185b02800
rdx         0
rcx         c
rax         0
r8          ffff80000e1965c0
r9          1
r10         2
r11         0
r12         ffff80000e1965c0
r13         fffffe81bdc82400
r14         0
r15         7
rip         ffffffff80610c3e    pmap_deactivate+0x93
cs          8
rflags      10246
rsp         fffffe810cc17ae0
ss          10
netbsd:pmap_deactivate+0x93:    movq    0(%rax),%rbx
db{2}> tr
pmap_deactivate() at netbsd:pmap_deactivate+0x93
mi_switch() at netbsd:mi_switch+0x2c5
kpreempt() at netbsd:kpreempt+0xe2
Xpreemptrecurse() at netbsd:Xpreemptrecurse+0x15
spawn_return() at netbsd:spawn_return+0x1eb

db{2}> ps          
PID    LID S CPU     FLAGS       STRUCT LWP *               NAME WAIT
25188    1 2   2         0   fffffe8185b02800      t_fileactions
26444>   1 7   2         0   fffffe81bdc82400      t_fileactions
(other CPUs are idle)
db{2}> ps /a
PID     COMMAND      STRUCT PROC *            UAREA *     VMSPACE/VM_MAP
25188t_fileacti   fffffe81822942e0   fffffe810cc17d80                  0
26444t_fileacti   fffffe8192b07540   fffffe810c7c1d80   fffffe81b0cc32e8

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--