[uClinux-dev] How to debug stack crashes, Coldfire platform

[fred basset]

Guys, I've started getting these crashes, are there any docs anywhere
on how to interpret this crash dump output?

# sed: page allocation failure. order:8, mode:0xd0
Stack from 4205bdcc:
4005b0f2 400553b6 402138ca 40738528 00000008 000000d0 00000008 00000000
000000c4 000c4000 000c4000 0000000c 43b29e34 00000000 4063986c 00000077
4205beac 00000000 00000010 00000000 4205b008 4205b000 00000000 00000100
00000000 4205b000 00000000 000200d0 4025c848 00000080 00000000 00000000
4005de52 000000d0 00000008 4025c844 00000000 00000001 0000550c 0007bc80
00000004 00003fb0 00015430 416cba00 4205bfcc 4205bf2a 00032a00 00000000
Call Trace with CONFIG_FRAME_POINTER disabled:

[4005b0f2] [400553b6] [402138ca] [4005de52] [40067d64]
[40093892] [4004b15e] [400390d8] [40020e70] [400677d8]
[40020e70] [401fc822] [40068468] [4006aa4e] [40020ea0]
[4002386c]
Mem-Info:
DMA per-cpu:
CPU 0: hi: 0, btch: 1 usd: 0
Active_anon:0 active_file:969 inactive_anon:0
inactive_file:0 dirty:0 writeback:0 unstable:0
free:8915 slab:561 mapped:0 pagetables:0 bounce:0
DMA free:35660kB min:1016kB low:1268kB high:1524kB active_anon:0kB
inactive_anon:0kB active_file:3876kB inactive_file:0kB present:65024kB
pages_scanned:0 all_unreclaimable? no
lowmem_reserve[]: 0 0 0
DMA: 23*4kB 106*8kB 132*16kB 117*32kB 97*64kB 43*128kB 31*256kB
18*512kB 0*1024kB 0*2048kB 0*4096kB 0*8192kB 0*16384kB = 35660kB
969 total pagecache pages
0 pages RAM
0 pages reserved
0 pages shared
0 pages non-shared
Allocation of length 802816 from process 1104 (sed) failed
DMA per-cpu:
CPU 0: hi: 0, btch: 1 usd: 0
Active_anon:0 active_file:969 inactive_anon:0
inactive_file:0 dirty:0 writeback:0 unstable:0
free:8915 slab:561 mapped:0 pagetables:0 bounce:0
DMA free:35660kB min:1016kB low:1268kB high:1524kB active_anon:0kB
inactive_anon:0kB active_file:3876kB inactive_file:0kB present:65024kB
pages_scanned:0 all_unreclaimable? no
lowmem_reserve[]: 0 0 0
DMA: 23*4kB 106*8kB 132*16kB 117*32kB 97*64kB 43*128kB 31*256kB
18*512kB 0*1024kB 0*2048kB 0*4096kB 0*8192kB 0*16384kB = 35660kB
969 total pagecache pages
Unable to allocate RAM for process text/data, errno 12

[Greg Ungerer]

Hi Fred,

Post by fred basset
Guys, I've started getting these crashes, are there any docs anywhere
on how to interpret this crash dump output?

I don't know of any. But there is quite a few clues in the dump
if you look closely.

Post by fred basset
# sed: page allocation failure. order:8, mode:0xd0
4005b0f2 400553b6 402138ca 40738528 00000008 000000d0 00000008 00000000
000000c4 000c4000 000c4000 0000000c 43b29e34 00000000 4063986c 00000077
4205beac 00000000 00000010 00000000 4205b008 4205b000 00000000 00000100
00000000 4205b000 00000000 000200d0 4025c848 00000080 00000000 00000000
4005de52 000000d0 00000008 4025c844 00000000 00000001 0000550c 0007bc80
00000004 00003fb0 00015430 416cba00 4205bfcc 4205bf2a 00032a00 00000000
[4005b0f2] [400553b6] [402138ca] [4005de52] [40067d64]
[40093892] [4004b15e] [400390d8] [40020e70] [400677d8]
[40020e70] [401fc822] [40068468] [4006aa4e] [40020ea0]
[4002386c]
CPU 0: hi: 0, btch: 1 usd: 0
Active_anon:0 active_file:969 inactive_anon:0
inactive_file:0 dirty:0 writeback:0 unstable:0
free:8915 slab:561 mapped:0 pagetables:0 bounce:0
DMA free:35660kB min:1016kB low:1268kB high:1524kB active_anon:0kB
inactive_anon:0kB active_file:3876kB inactive_file:0kB present:65024kB
pages_scanned:0 all_unreclaimable? no
lowmem_reserve[]: 0 0 0
DMA: 23*4kB 106*8kB 132*16kB 117*32kB 97*64kB 43*128kB 31*256kB
18*512kB 0*1024kB 0*2048kB 0*4096kB 0*8192kB 0*16384kB = 35660kB
969 total pagecache pages
0 pages RAM
0 pages reserved
0 pages shared
0 pages non-shared
Allocation of length 802816 from process 1104 (sed) failed

^^^^^^
Your process is trying to allocate about 800k bytes in a single
allocation. But when you look at the slab sizes available in the list

Post by fred basset
DMA: 23*4kB 106*8kB 132*16kB 117*32kB 97*64kB 43*128kB 31*256kB
18*512kB 0*1024kB 0*2048kB 0*4096kB 0*8192kB 0*16384kB = 35660kB

You have none that can satisfy this. The largest chunks you have
available are 512k. This is almost certainly due to the free memory
regions becoming fragmented over time, given you have a reasonably
large size of memory to start with.

Regards
Greg

Post by fred basset
CPU 0: hi: 0, btch: 1 usd: 0
Active_anon:0 active_file:969 inactive_anon:0
inactive_file:0 dirty:0 writeback:0 unstable:0
free:8915 slab:561 mapped:0 pagetables:0 bounce:0
DMA free:35660kB min:1016kB low:1268kB high:1524kB active_anon:0kB
inactive_anon:0kB active_file:3876kB inactive_file:0kB present:65024kB
pages_scanned:0 all_unreclaimable? no
lowmem_reserve[]: 0 0 0
DMA: 23*4kB 106*8kB 132*16kB 117*32kB 97*64kB 43*128kB 31*256kB
18*512kB 0*1024kB 0*2048kB 0*4096kB 0*8192kB 0*16384kB = 35660kB
969 total pagecache pages
Unable to allocate RAM for process text/data, errno 12
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