Sleeping BUG in khugepaged for i586

Larry Finger
2017-06-03T19:24:30Z

I recently turned on locking diagnostics for a Dell Latitude D600 laptop, which
requires a 32-bit kernel. In the log I found the following:

BUG: sleeping function called from invalid context at mm/khugepaged.c:655
in_atomic(): 1, irqs_disabled(): 0, pid: 20, name: khugepaged
1 lock held by khugepaged/20:
#0: (&mm->mmap_sem){++++++}, at: [<c03d6609>]
collapse_huge_page.isra.47+0x439/0x1240
CPU: 0 PID: 20 Comm: khugepaged Tainted: G W
4.12.0-rc1-wl-12125-g952a068 #80
Hardware name: Dell Computer Corporation Latitude D600
/03U652, BIOS A05 05/29/2003
Call Trace:
dump_stack+0x76/0xb2
___might_sleep+0x174/0x230
collapse_huge_page.isra.47+0xacf/0x1240
khugepaged_scan_mm_slot+0x41e/0xc00
? _raw_spin_lock+0x46/0x50
khugepaged+0x277/0x4f0
? prepare_to_wait_event+0xe0/0xe0
kthread+0xeb/0x120
? khugepaged_scan_mm_slot+0xc00/0xc00
? kthread_create_on_node+0x30/0x30
ret_from_fork+0x21/0x30

I have no idea when this problem was introduced. Of course, I will test any
proposed fixes.

Thanks,

Larry