Re: Too much memory causes crash when reading/writing to disk

From: Jeff Lessem (Jeff.Lessem@Colorado.EDU)
Date: Tue Jul 17 2001 - 08:22:42 EST

Andrew Morton wrote:
>> I have done a bit more work on the problem I reported in my message
>> "Crashes reading and writing to disk". To recap, on a machine with
>> 8GB of RAM, either
>> dd if=/dev/zero bs=1G count=10 | split -b 1073741824
>> or
>> find /bigfulldisk -type f -exec cat {} \; > /dev/null
>> can reliably cause a crash.
>It seems that one of your CPUs is stuck in an interrupt
>routine. Could you please try running with the below
>patch? Feed the output through ksymoops.

I tried the patch, but the machine came up in a very confused state.
It couldn't mount proc, and other badness. I made the patch against
2.4.6, because 2.4.7-pre6 doesn't boot at all (I guess I should send
another message about that problem).

>Also (but separately) try enabling the NMI watchdog with
>the `nmi_watchdog=1' kernel boot parameter.

This worked, and I recreated the crash:

ksymoops 2.4.1 on i686 2.4.6. Options used
     -V (default)
     -k /proc/ksyms (default)
     -l /proc/modules (default)
     -o /lib/modules/2.4.6/ (default)
     -m /boot/ (default)

Warning: You did not tell me where to find symbol information. I will
assume that the log matches the kernel and modules that are running
right now and I'll use the default options above for symbol resolution.
If the current kernel and/or modules do not match the log, you can get
more accurate output by telling me the kernel version and where to find
map, modules, ksyms etc. ksymoops -h explains the options.

7552MB HIGHMEM available.
activating NMI Watchdog ... done.
cpu: 0, clocks: 999966, slice: 111107
cpu: 5, clocks: 999966, slice: 111107
cpu: 6, clocks: 999966, slice: 111107
cpu: 7, clocks: 999966, slice: 111107
cpu: 3, clocks: 999966, slice: 111107
cpu: 2, clocks: 999966, slice: 111107
cpu: 1, clocks: 999966, slice: 111107
cpu: 4, clocks: 999966, slice: 111107
NMI Watchdog detected LOCKUP on CPU5, registers:
CPU: 5
EIP: 0010:[<c010b50f>]
Using defaults from ksymoops -t elf32-i386 -a i386
EFLAGS: 00000046
eax: 00000080 ebx: c9c93f7c ecx: 04b058ee edx: 000019c0
esi: 20000001 edi: 000000a0 ebp: 00000000 esp: c9c93f2c
ds: 0018 es: 0018 ss: 0018
Process swapper (pid: 0, stackpage=c9c93000)
Stack: c0247e28 c01083b1 00000000 00000000 c9c93f7c c02af980 c0291800 00000000
       c9c93f74 c0108596 00000000 c9c93f7c c0247e28 c0105180 c9c92000 c0105180
       000000a0 c0247e28 00000000 c0106d04 c0105180 00000020 c9c92000 c9c92000
Call Trace: [<c01083b1>] [<c0108596>] [<c0105180>] [<c0105180>] [<c0106d04>] [<c0105180>] [<c0105180>]
       [<c01051ac>] [<c0105212>] [<c0114e66>]
Code: c6 05 00 79 24 c0 01 53 e8 80 09 01 00 83 c4 04 83 3d 88 f2

>>EIP; c010b50f <timer_interrupt+9b/130> <=====
Trace; c01083b1 <handle_IRQ_event+4d/78>
Trace; c0108596 <do_IRQ+a6/ec>
Trace; c0105180 <default_idle+0/34>
Trace; c0105180 <default_idle+0/34>
Trace; c0106d04 <ret_from_intr+0/7>
Trace; c0105180 <default_idle+0/34>
Trace; c0105180 <default_idle+0/34>
Trace; c01051ac <default_idle+2c/34>
Trace; c0105212 <cpu_idle+3e/54>
Trace; c0114e66 <printk+16e/17c>
Code; c010b50f <timer_interrupt+9b/130>
00000000 <_EIP>:
Code; c010b50f <timer_interrupt+9b/130> <=====
   0: c6 05 00 79 24 c0 01 movb $0x1,0xc0247900 <=====
Code; c010b516 <timer_interrupt+a2/130>
   7: 53 push %ebx
Code; c010b517 <timer_interrupt+a3/130>
   8: e8 80 09 01 00 call 1098d <_EIP+0x1098d> c011be9c <do_timer+0/30>
Code; c010b51c <timer_interrupt+a8/130>
   d: 83 c4 04 add $0x4,%esp
Code; c010b51f <timer_interrupt+ab/130>
  10: 83 3d 88 f2 00 00 00 cmpl $0x0,0xf288

1 warning issued. Results may not be reliable.
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This archive was generated by hypermail 2b29 : Mon Jul 23 2001 - 21:00:08 EST