Kernel BUG: scheduling while atomic

Kareem Shehata kshehata at
Wed Feb 18 15:25:42 EST 2009

Hey Dan,

As Dave Kroetsch mentioned, we've gotten some very strange results at  
Aeryon using a Unex 8385 CF module on an arm processor.  Specifically,  
setting the kernel tick to 1000 Hz (CONFIG_HZ = 1000) produces a  
"scheduling while atomic" bug when setting the ssid for the second  
time after boot, the messages for which are below.  Also, enabling  
debug messages for libertas (LIBERTAS_DEBUG=y) seems to make any  
filetransfer very slow, around 15 kB/s, whether or not any debug  
message flags are enabled.  Are these known issues, and if not how do  
we go about solving them?



[  120.625000] BUG: scheduling while atomic: iwconfig/0x00000001/1728
[  120.631000] [<c0028d54>] (dump_stack+0x0/0x14) from [<c02907e4>]  
[  120.640000] [<c0290780>] (schedule+0x0/0x678) from [<bf01ec4c>]  
(__lbs_cmd+0x118/0x21c [libertas])
[  120.649000] [<bf01eb34>] (__lbs_cmd+0x0/0x21c [libertas]) from  
[<bf019df4>] (lbs_get_wireless_stats+0x1a8/0x354 [libertas])
[  120.660000] [<bf019c4c>] (lbs_get_wireless_stats+0x0/0x354  
[libertas]) from [<c0289448>] (get_wireless_stats+0x2c/0x38)
[  120.671000]  r8:00000002 r7:00000400 r6:4001e000 r5:c2f3f2e0  
[  120.678000] [<c028941c>] (get_wireless_stats+0x0/0x38) from  
[<c028a310>] (wireless_seq_show+0x38/0x108)
[  120.688000] [<c028a2d8>] (wireless_seq_show+0x0/0x108) from  
[<c00ac074>] (seq_read+0x230/0x388)
[  120.697000] [<c00abe44>] (seq_read+0x0/0x388) from [<c008ef94>]  
[  120.705000] [<c008eee0>] (vfs_read+0x0/0x144) from [<c008f3d4>]  
[  120.713000]  r7:00000000 r6:00000000 r5:fffffff7 r4:c2aed720
[  120.718000] [<c008f390>] (sys_read+0x0/0x70) from [<c0024ea0>]  
[  120.727000]  r7:00000003 r6:000003ff r5:00000000 r4:00015008

The attached text file has the debug messages before and after the  
BUG.  Search for "scheduling while atomic", it's near the middle.
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Kareem Shehata
Aeryon Labs Inc.
519-489-6726 x254

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