Jun,
' Got the BUG() again after about 5 hours of operation. The BUG()
report is below. Any additional insight you can provide is greatly
appreciated. Thanks again for your help.
Jack
Linux version 2.4.17 (jack@saturn) (gcc version 3.2.2 20030612 (Pioneer
Voyager)) #5 Fri Jul 18 12:51:00 PDT 2003
active_mm = 83f02b20
ksymoops 2.4.6 on mips 2.4.17. Options used
-v vmlinux (specified)
-k /proc/ksyms (default)
-l /proc/modules (default)
-o /lib/modules/2.4.17/ (default)
-m System.map (specified)
-T 32
kernel BUG at sched.c:786!
Unable to handle kernel paging request at virtual address 00000000, epc ==
80014c18, ra == 80014c18
$0 : 00000000 b001f800 0000001b 00000001 83a6a000 00000000 00000001 0000144d
$8 : 0000144d ffffd44d 0000144d 00000000 00000000 00000000 801d1119 fffffff9
$16: 00000000 00000000 80b5a000 83f02b20 80008000 00000000 80008000 1001ccf8
$24: 0000000a 80b5bb52 80b5a000 80b5bc80 80b5bc80 80014c18
epc : 80014c18 Tainted: P
Using defaults from ksymoops -t elf32-tradbigmips -a mips:3000
Status: b001f803
Cause : 8000040c
Process pvrd (pid: 232, stackpage=80b5a000)
Stack: 80174bd8 80174bf0 00000312 83f02b20 00000001 7fffffff 83f14d40
00000000
00000002 80b5be84 80b5bda0 80b5bcb8 8001489c 00000002 00000001
c0052dd8
01f8a120 00000001 83c349a0 00000001 c0106008 00000001 00000000
00000001
00000001 7fffffff 83f14d40 7dfff820 c002071c c0105ff4 a1f8a120
80b5be80
80b5bd08 00000001 00000000 80b5a000 83f14d40 83f14d40 0000009c
00000001
c0105f30 ...
Call Trace: [<80174bd8>] [<80174bf0>] [<8001489c>] [<c0052dd8>] [<c0106008>]
[<c002071c>]
[<c0105ff4>] [<c0105f30>] [<c0078798>] [<c01192fc>] [<c01192fc>]
[<c00781e0>]
[<800e892c>] [<c01192fc>] [<c0072264>] [<c0072394>] [<c01192fc>]
[<c0073984>]
[<c01562f0>] [<c0155000>] [<c0157228>] [<80057ab0>] [<800de4ec>]
[<c01552f0>]
[<c0155000>] [<80041e14>] [<80041cd4>] [<c015521c>] [<80028934>]
[<800d5d50>]
[<c015621c>] [<c0155000>] [<80014834>] [<800d59a0>] [<c008422d>]
[<c00494ac>]
[<8004e808>] [<8004e814>] [<8000f0e4>] [<c008422d>]
Code: 24a54bf0 0c0061b9 24060312 <080052f5> ae200000 40016000 00000000
3421001f 3821001e
>>RA; 80014c18 <schedule+348/488>
>>$1; b001f800 <_end+2fe24ea0/3fe246a0>
>>$4; 83a6a000 <_end+386f6a0/3fe246a0>
>>$14; 801d1119 <printk_buf.1+19/400>
>>$18; 80b5a000 <_end+95f6a0/3fe246a0>
>>$19; 83f02b20 <_end+3d081c0/3fe246a0>
>>$20; 80008000 <init_task_union+0/0>
>>$22; 80008000 <init_task_union+0/0>
>>$23; 1001ccf8 <_binary_ramdisk_gz_size+1001a6da/7fffe9e2>
>>$25; 80b5bb52 <_end+9611f2/3fe246a0>
>>$28; 80b5a000 <_end+95f6a0/3fe246a0>
>>$29; 80b5bc80 <_end+961320/3fe246a0>
>>$30; 80b5bc80 <_end+961320/3fe246a0>
>>$31; 80014c18 <schedule+348/488>
>>PC; 80014c18 <schedule+348/488> <=====
Trace; 80174bd8 <mips_io_port_base+cf8/1c30>
Trace; 80174bf0 <mips_io_port_base+d10/1c30>
Trace; 8001489c <schedule_timeout+dc/e4>
Trace; c0052dd8 <[bcm7030]TransPvrAddBuffer+1b0/55c>
Trace; c0106008 <[bcm7030]gPvrPlaybackVars+d8/1e0>
Trace; c002071c <[pdtutil]pdtKNIWaitForEvent+e8/114>
Trace; c0105ff4 <[bcm7030]gPvrPlaybackVars+c4/1e0>
Trace; c0105f30 <[bcm7030]gPvrPlaybackVars+0/1e0>
Trace; c0078798 <[bcm7030]pvr_playbackWaitForFreeDescriptor+94/240>
Trace; c01192fc <[bcm7030]glNoiseLevels+c5c/1eaf>
Trace; c01192fc <[bcm7030]glNoiseLevels+c5c/1eaf>
Trace; c00781e0 <[bcm7030]pvr_playbackAddDataRequest+2f4/34c>
Trace; 800e892c <ide_do_request+1c0/3d0>
Trace; c01192fc <[bcm7030]glNoiseLevels+c5c/1eaf>
Trace; c0072264 <[bcm7030]brcm_play_getbuffer+3c/60>
Trace; c0072394 <[bcm7030]brcm_play_feeddata+10c/114>
Trace; c01192fc <[bcm7030]glNoiseLevels+c5c/1eaf>
Trace; c0073984 <[bcm7030]brcm_play_ioctl+de4/1400>
Trace; c01562f0 <END_OF_CODE+1ac41/????>
Trace; c0155000 <END_OF_CODE+19951/????>
Trace; c0157228 <END_OF_CODE+1bb79/????>
Trace; 80057ab0 <kiobuf_wait_for_io+8c/cc>
Trace; 800de4ec <submit_bh+84/e4>
Trace; c01552f0 <END_OF_CODE+19c41/????>
Trace; c0155000 <END_OF_CODE+19951/????>
Trace; 80041e14 <brw_kiovec+2e8/3c8>
Trace; 80041cd4 <brw_kiovec+1a8/3c8>
Trace; c015521c <END_OF_CODE+19b6d/????>
Trace; 80028934 <unmap_kiobuf+58/98>
Trace; 800d5d50 <rw_raw_dev+36c/3ac>
Trace; c015621c <END_OF_CODE+1ab6d/????>
Trace; c0155000 <END_OF_CODE+19951/????>
Trace; 80014834 <schedule_timeout+74/e4>
Trace; 800d59a0 <raw_read+2c/38>
Trace; c008422d <[bcm7030]scard_interrupt+11/340>
Trace; c00494ac <[bcm7030]b7030_ioctl+3c/108>
Trace; 8004e808 <sys_ioctl+9c/234>
Trace; 8004e814 <sys_ioctl+a8/234>
Trace; 8000f0e4 <stack_done+1c/38>
Trace; c008422d <[bcm7030]scard_interrupt+11/340>
Code; 80014c0c <schedule+33c/488>
00000000 <_PC>:
Code; 80014c0c <schedule+33c/488>
0: 24a54bf0 addiu a1,a1,19440
Code; 80014c10 <schedule+340/488>
4: 0c0061b9 jal 186e4 <_PC+0x186e4> 8002d2f0
<grab_cache_page_nowait+c0/12c>
Code; 80014c14 <schedule+344/488>
8: 24060312 li a2,786
Code; 80014c18 <schedule+348/488> <=====
c: 080052f5 j 14bd4 <_PC+0x14bd4> 800297e0 <do_swap_page+b4/1c8>
<=====
Code; 80014c1c <schedule+34c/488>
10: ae200000 sw zero,0(s1)
Code; 80014c20 <schedule+350/488>
14: 40016000 mfc0 at,$12
Code; 80014c24 <schedule+354/488>
18: 00000000 nop
Code; 80014c28 <schedule+358/488>
1c: 3421001f ori at,at,0x1f
Code; 80014c2c <schedule+35c/488>
20: 3821001e xori at,at,0x1e
> -----Original Message-----
> From: Jun Sun [mailto:jsun@mvista.com]
> Sent: Friday, July 18, 2003 11:30 AM
> To: Jack Miller
> Cc: Linux-Mips; jsun@mvista.com
> Subject: Re: kernel BUG at sched.c:784!
>
>
> On Fri, Jul 18, 2003 at 10:48:22AM -0700, Jack Miller wrote:
> > Jun,
> > Here is the excerpt from sched.c:
> >
> > prepare_to_switch();
> > {
> > struct mm_struct *mm = next->mm;
> > struct mm_struct *oldmm = prev->active_mm;
> > if (!mm) {
> > 784 if (next->active_mm) BUG();
> > next->active_mm = oldmm;
> > atomic_inc(&oldmm->mm_count);
> > enter_lazy_tlb(oldmm, next, this_cpu);
> >
> > Jack
> >
>
> Jack,
>
> Plese change that line to
> if (next->active_mm) {
> printk("active_mm = %p\n", next->active_mm);
> BUG();
> }
>
> If you see next->active_mm to be NULL, you are seeing the CPU bug.
>
> However, given the frequency you are seeing the problem, I suspect it
> is something else.
>
> Whenever CPU runs out active processes to run, it will switch to idle
> process, which does not have a mm. The BUG() basically says "last time
> when idle process was switched off, its active_mm pointer should be set
> NULL". The dropping active_mm code is shortly after the above chunk.
>
> Jun
>
> > > -----Original Message-----
> > > From: Jun Sun [mailto:jsun@mvista.com]
> > > Sent: Friday, July 18, 2003 10:45 AM
> > > To: Jack Miller
> > > Cc: Linux-Mips; jsun@mvista.com
> > > Subject: Re: kernel BUG at sched.c:784!
> > >
> > >
> > > On Fri, Jul 18, 2003 at 10:26:59AM -0700, Jack Miller wrote:
> > > > Jun,
> > > > Thanks for your response. Our kernel is actually based upon the
> > > > MontaVista kernel and that workaround is in place.
> > > >
> > > > Jack
> > > >
> > >
> > > Which line is 784? There is another cpu bug which might cause this.
> > >
> > > I checked our sherman source tree and did not find the corresponding
> > > line.
> > >
> > > Jun
> > >
> > > > > -----Original Message-----
> > > > > From: linux-mips-bounce@linux-mips.org
> > > > > [mailto:linux-mips-bounce@linux-mips.org]On Behalf Of Jun Sun
> > > > > Sent: Friday, July 18, 2003 10:23 AM
> > > > > To: Jack Miller
> > > > > Cc: Linux-Mips; jsun@mvista.com
> > > > > Subject: Re: kernel BUG at sched.c:784!
> > > > >
> > > > >
> > > > >
> > > > > Your kernel looks old, and probably don't have the CPU
> bug workaround
> > > > > code at the beginning of vec3 exception handler.
> > > > >
> > > > > NESTED(except_vec3_generic, 0, sp)
> > > > > #if R5432_CP0_INTERRUPT_WAR
> > > > > mfc0 k0, CP0_INDEX
> > > > > #endif
> > > > >
> > > > > Try this.
> > > > >
> > > > > Jun
> > > > >
> > > > > On Fri, Jul 18, 2003 at 09:57:01AM -0700, Jack Miller wrote:
> > > > > > We are developing a system based around a NEC VR5432 CPU
> > > and Broadcom
> > > > > > BCM703X System Controller. When the system is running with
> > > the intended
> > > > > > application and drivers we intermittently experience a kernel
> > > > > OOPS in the
> > > > > > scheduler. Would someone please provide some insight to the
> > > > > following OOPS
> > > > > > ? It appears (with my limited understanding of the
> > > scheduler) that the
> > > > > > scheduler is trying to schedule the 'idle' task. What
> > > > > condition prevails to
> > > > > > cause this to happen ?
> > > > > >
> > > > > > Using a J-TAG Debugger, I "walked" the task list (in both
> > > > > directions) and
> > > > > > everthing appears to be in order.
> > > > > >
> > > > > > Thanks in advance for your help.
> > > > > >
> > > > > > Regards,
> > > > > > Jack
> > > > > >
> > > > > >
> > > > > > Linux version 2.4.17 (jack@saturn) (gcc version 3.2.2
> > > 20030322 (Pioneer
> > > > > > Voyager)) #1 Fri May 30 14:55:32 PDT 2003
> > > > > > ksymoops 2.4.6 on mips 2.4.17. Options used
> > > > > > -v vmlinux (specified)
> > > > > > -k /proc/ksyms (default)
> > > > > > -l /proc/modules (default)
> > > > > > -o /lib/modules/2.4.17/ (default)
> > > > > > -m System.map (specified)
> > > > > > -T 32
> > > > > >
> > > > > > root@stb2073:~# kernel BUG at sched.c:784!
> > > > > > Unable to handle kernel paging request at virtual address
> > > > > 00000000, epc ==
> > > > > > 8001524c, ra == 8001524c
> > > > > > $0 : 00000000 b001f800 0000001b 00000000 ffffff9d 80008000
> > > > > 0000001f 828f4a20
> > > > > > $8 : 00000001 ffffd890 00001890 801cb119 00000000 00000000
> > > > > fffffff9 ffffffff
> > > > > > $16: 00000000 00000000 809ae000 828f4a20 80008000 00000000
> > > > > 80008000 1001ccf8
> > > > > > $24: 0000000a 00000002 809ae000 809afe90
> > > > > 809afe90 8001524c
> > > > > > epc : 8001524c Tainted: P
> > > > > > Using defaults from ksymoops -t elf32-tradbigmips -a mips:3000
> > > > > > Status: b001f803
> > > > > > Cause : 8000c40c
> > > > > > Process pvrd (pid: 331, stackpage=809ae000)
> > > > > > Stack: 8016eda8 8016edc0 00000310 fffffc18 00138f80
> > > 00000002 809afed8
> > > > > > 00000070
> > > > > > 00000000 1001cd00 1001ccfc 809afec8 80014e74
> > > 80014e6c 00000400
> > > > > > 00000200
> > > > > > c008422b 80bd4160 00000000 00000000 00138f80
> > > 809ae000 80014dd4
> > > > > > 2aac2000
> > > > > > 00000000 809aff18 00001807 7edffa50 8002242c
> > > 00000070 00000000
> > > > > > 8016c290
> > > > > > 00000000 00000000 00000000 00989680 7edffa40
> > > 00000000 8000f7c4
> > > > > > 8000f7c4
> > > > > > 00000000 ...
> > > > > > Call Trace: [<8016eda8>] [<8016edc0>] [<80014e74>] [<80014e6c>]
> > > > > [<c008422b>]
> > > > > > [<80014dd4>]
> > > > > > [<8002242c>] [<8016c290>] [<8000f7c4>] [<8000f7c4>]
> > > > > > Code: 24a5edc0 0c0062f7 24060310 <08005485> ae200000
> > > > > 40016000 00000000
> > > > > > 3421001f 3821001e
> > > > > >
> > > > > >
> > > > > > >>RA; 8001524c <schedule+33c/47c>
> > > > > > >>$1; b001f800 <_end+2fe2aea0/3fe2a6a0>
> > > > > > >>$5; 80008000 <init_task_union+0/0>
> > > > > > >>$7; 828f4a20 <_end+27000c0/3fe2a6a0>
> > > > > > >>$11; 801cb119 <printk_buf.4+19/400>
> > > > > > >>$18; 809ae000 <_end+7b96a0/3fe2a6a0>
> > > > > > >>$19; 828f4a20 <_end+27000c0/3fe2a6a0>
> > > > > > >>$20; 80008000 <init_task_union+0/0>
> > > > > > >>$22; 80008000 <init_task_union+0/0>
> > > > > > >>$23; 1001ccf8 <_binary_ramdisk_gz_size+1001a6da/7fffe9e2>
> > > > > > >>$28; 809ae000 <_end+7b96a0/3fe2a6a0>
> > > > > > >>$29; 809afe90 <_end+7bb530/3fe2a6a0>
> > > > > > >>$30; 809afe90 <_end+7bb530/3fe2a6a0>
> > > > > > >>$31; 8001524c <schedule+33c/47c>
> > > > > >
> > > > > > >>PC; 8001524c <schedule+33c/47c> <=====
> > > > > >
> > > > > > Trace; 8016eda8 <mips_io_port_base+d08/1c30>
> > > > > > Trace; 8016edc0 <mips_io_port_base+d20/1c30>
> > > > > > Trace; 80014e74 <schedule_timeout+74/e4>
> > > > > > Trace; 80014e6c <schedule_timeout+6c/e4>
> > > > > > Trace; c008422b <[bcm7030]scard_interrupt+f/340>
> > > > > > Trace; 80014dd4 <process_timeout+0/2c>
> > > > > > Trace; 8002242c <sys_nanosleep+170/1fc>
> > > > > > Trace; 8016c290 <mips_hwi4_dispatch+70/78>
> > > > > > Trace; 8000f7c4 <stack_done+1c/38>
> > > > > > Trace; 8000f7c4 <stack_done+1c/38>
> > > > > >
> > > > > > Code; 80015240 <schedule+330/47c>
> > > > > > 00000000 <_PC>:
> > > > > > Code; 80015240 <schedule+330/47c>
> > > > > > 0: 24a5edc0 addiu a1,a1,-4672
> > > > > > Code; 80015244 <schedule+334/47c>
> > > > > > 4: 0c0062f7 jal 18bdc <_PC+0x18bdc> 8002de1c
> > > > > > <generic_file_direct_IO+294/2d8>
> > > > > > Code; 80015248 <schedule+338/47c>
> > > > > > 8: 24060310 li a2,784
> > > > > > Code; 8001524c <schedule+33c/47c> <=====
> > > > > > c: 08005485 j 15214 <_PC+0x15214> 8002a454
> > > > > <__vma_link+9c/e0>
> > > > > > <=====
> > > > > > Code; 80015250 <schedule+340/47c>
> > > > > > 10: ae200000 sw zero,0(s1)
> > > > > > Code; 80015254 <schedule+344/47c>
> > > > > > 14: 40016000 mfc0 at,$12
> > > > > > Code; 80015258 <schedule+348/47c>
> > > > > > 18: 00000000 nop
> > > > > > Code; 8001525c <schedule+34c/47c>
> > > > > > 1c: 3421001f ori at,at,0x1f
> > > > > > Code; 80015260 <schedule+350/47c>
> > > > > > 20: 3821001e xori at,at,0x1e
> > > > > >
> > > > > >
> > > > > > Jack Miller <jack.miller@pioneer-pdt.com>
> > > > > > Pioneer Digital Technologies, Inc.
> > > > > > 6170 Cornerstone Court East
> > > > > > Suite 330
> > > > > > San Diego, CA 92121-3767
> > > > > > vox: (858)824-0790 x356
> > > > > > fax: (858)824-0796
> > > > > >
> > > > > >
> > > > >
> > > >
> > >
> >
>
