root@titan:~$ cat /proc/1/wchan
p->thead.sp: 0x8ffd9ae4
schedule_frame: 0x989657
Fault in unaligned fixup: 0000 [#7]
Modules linked in: vfat fat nls_base sd_mod

Pid : 2857, Comm:                  cat
PC is at get_wchan+0x6e/0xa0
PC  : 8803384e SP  : 8f819ea0 SR  : 40008100 TEA : c01098a4    Not tainted
R0  : 00000000 R1  : 882669e0 R2  : 40008100 R3  : 00000000
R4  : 88264ad4 R5  : 000049fa R6  : ffffffff R7  : 000000f0
R8  : 00000000 R9  : 00989657 R10 : 88040840 R11 : 88044100
R12 : fffffff4 R13 : 00416000 R14 : 8f819f84
MACH: 00000110 MACL: 00000000 GBR : 296ba440 PR  : 88033848

Call trace:
[<880b9330>] proc_pid_wchan+0x10/0xa0
[<8806b58e>] __alloc_pages+0x4e/0x2c0
[<8806b81c>] __get_free_pages+0x1c/0x80
[<880b97ec>] proc_info_read+0x4c/0xe0
[<8808655a>] vfs_read+0x7a/0x140
[<88086874>] sys_read+0x34/0x80
[<880381e0>] syscall_call+0xc/0x10
[<88086840>] sys_read+0x0/0x80

Process: cat (pid: 2857, stack limit = 8f818001)
Stack: (0x8f819ea0 to 0x8f81a000)
9ea0: 880b9330 00000c00 8ffe6cc0 8fc78000 8fc94c58 00000002 00000000 88552aa0
9ec0: 00000000 00000000 00008001 00000044 000200d0 00000000 00000044 882af49c
9ee0: 00000000 00000000 00000001 00000000 00000001 00000001 8806b58e 00000000
9f00: 00416000 8840e9a0 000000d0 8ffe6cc0 00001000 882af49c 00000000 882af49c
9f20: 00000010 2faf0800 8806b81c 8f819f84 00416000 fffffff4 00000c00 8ffe6cc0
9f40: 880b97ec 8fc78000 8fc94c58 8808655a 00400d74 00400e00 00400b60 8f819f84
9f60: 00416000 00001000 8eaa03e0 88086874 fffffff7 00001000 00416000 8eaa03e0
9f80: 00000000 00000000 00000000 880381e0 ffffff0f 00000001 8f819ff8 88086840
9fa0: 00000000 00000440 00000416 00000003 00000003 00416000 00001000 7bbd0d3c
9fc0: 00001000 00416000 00416000 00000003 00400b60 00400e00 00400d74 7bbd0ce4
9fe0: 2964e114 00402fdc 00000001 296ba440 00000110 00416000 0000004c 00000160
 Segmentation fault
root@titan:~$