> After a little investigation regarding the cron job which appeared to
> be running when I first encountered this oops yesterday morning, I
> discovered that in fact two scripts get fired off by cron at the same
> time. They both do a ps as their first command. This prompted me to
> try doing multiple ps commands at the same time. Bingo.
>
> Here's a small script which will oops my machine in 5-60 seconds.
> This occurs with 2.2.0, 2.2.0ac1 and 2.2.0ac2 kernels:
>
> #!/bin/bash
>
> while true ; do
>
> ps alx | cat >/dev/null &
> ps auxww | cat >/dev/null &
> ps alx | cat >/dev/null &
> ps auxww | cat >/dev/null &
> ps alx | cat >/dev/null &
> ps auxww | cat >/dev/null &
> wait
> echo -n x
>
> done
>
We also has 2 crash this week with the same oops. When I ran your
script it took around 10 seconds to crash. The computer is a Dell
Precision 410 dual PII 450 MHz with 256 Mb of RAM.
Here is the oops. If you want more debug info, feel free to contact
me, I can perform tests to help pin point the problem
Jan 27 17:55:16 p1580 kernel: free_one_pmd: bad directory entry c4996000
Jan 27 17:55:16 p1580 kernel: kmem_free: Bad obj addr (objp=c46aa840, name=mm_struct)
Jan 27 17:55:16 p1580 kernel: Unable to handle kernel NULL pointer dereference at virtual address 00000000
Jan 27 17:55:16 p1580 kernel: current->tss.cr3 = 04b07000, `r3 = 04b07000
Jan 27 17:55:16 p1580 kernel: *pde = 00000000
Jan 27 17:55:16 p1580 kernel: Oops: 0002
Jan 27 17:55:16 p1580 kernel: CPU: 0
Jan 27 17:55:16 p1580 kernel: EIP: 0010:[<c01212bf>]
Jan 27 17:55:16 p1580 kernel: EFLAGS: 00010282
Jan 27 17:55:16 p1580 kernel: eax: 0000003b ebx: c048f6e0 ecx: c01eeac6 edx: c337a000
Jan 27 17:55:16 p1580 kernel: esi: c46aa840 edi: 00000282 ebp: 00000000 esp: c4d0dee8
Jan 27 17:55:16 p1580 kernel: ds: 0018 es: 0018 ss: 0018
Jan 27 17:55:16 p1580 kernel: Process ps (pid: 627, process nr: 56, stackpage=c4d0d000)
Jan 27 17:55:16 p1580 kernel: Stack: c4e4c000 000007ff 00000000 c46aa8bc 00000000 c01127a5 c048f6e0 c46aa840
Jan 27 17:55:16 p1580 kernel: c46aa840 c46aa840 c46aa840 c46aa840 c0142922 c46aa840 c0142a9b c46aa840
Jan 27 17:55:16 p1580 kernel: c46aa840 bffffa2f bffffa33 c4e4c000 00000274 c4e4c000 c01d1e18 c0143b83
Jan 27 17:55:16 p1580 kernel: Call Trace: [<c01127a5>] [<c0142922>] [<c0142a9b>] [<c0143b83>] [<c0143c95>] [<c01253e6>] [<c0125b5a>]
Jan 27 17:55:16 p1580 kernel: [<c0107aec>]
Jan 27 17:55:16 p1580 kernel: Code: c7 05 00 00 00 00 00 00 00 00 5b 5e 5f 5d 83 c4 0c c3 8d 76
Jan 27 17:55:19 p1580 kernel: free_one_pmd: bad directory entry c4dc6000
Jan 27 17:55:19 p1580 kernel: kmem_free: Bad obj addr (objp=c46aabc0, name=mm_struct)
Jan 27 17:55:19 p1580 kernel: Unable to handle kernel NULL pointer dereference at virtual address 00000000
Jan 27 17:55:19 p1580 kernel: current->tss.cr3 = 04e9f000, `r3 = 04e9f000
Jan 27 17:55:19 p1580 kernel: *pde = 00000000
Jan 27 17:55:19 p1580 kernel: Oops: 0002
Jan 27 17:55:19 p1580 kernel: CPU: 1
Jan 27 17:55:19 p1580 kernel: EIP: 0010:[<c01212bf>]
Jan 27 17:55:19 p1580 kernel: EFLAGS: 00010286
Jan 27 17:55:19 p1580 kernel: eax: 0000003b ebx: c048f6e0 ecx: c01eeac6 edx: c337a000
Jan 27 17:55:19 p1580 kernel: esi: c46aabc0 edi: 00000286 ebp: 00000000 esp: c4ec7ee8
Jan 27 17:55:19 p1580 kernel: ds: 0018 es: 0018 ss: 0018
Jan 27 17:55:19 p1580 kernel: Process ps (pid: 861, process nr: 51, stackpage=c4ec7000)
Jan 27 17:55:19 p1580 kernel: Stack: c4e41000 000007ff 00000000 c46aac3c 00000000 c01127a5 c048f6e0 c46aabc0
Jan 27 17:55:19 p1580 kernel: c46aabc0 c46aabc0 c46aabc0 c46aabc0 c0142922 c46aabc0 c0142a9b c46aabc0
Jan 27 17:55:19 p1580 kernel: c46aabc0 bffffa2f bffffa33 c4e41000 0000035e c4e41000 c01d1e18 c0143b83
Jan 27 17:55:19 p1580 kernel: Call Trace: [<c01127a5>] [<c0142922>] [<c0142a9b>] [<c0143b83>] [<c0143c95>] [<c01253e6>] [<c0125b5a>]
Jan 27 17:55:19 p1580 kernel: [<c0107aec>]
Jan 27 17:55:19 p1580 kernel: Code: c7 05 00 00 00 00 00 00 00 00 5b 5e 5f 5d 83 c4 0c c3 8d 76
Thank you for your help,
Claude
-- Claude Gamache, CAE Electronique Ltee, 8585 Cote-de-Liesse Saint-Laurent, Quebec, Canada H4T 1G6 Email: cgamache@cae.ca Tel.: (514) 341-2000 x3194, Fax: (514) 734-5612- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/