sleeping function called from invalid context ?

[Dave Hawkes]

Hi All,

If I use kernel-2.6.8-1.521 or kernel-2.6.7-1.494.2.2 with FC2 I get the 
following error logged about every second to the console:

Aug 22 09:40:22 localhost kernel: Debug: sleeping function called from 
invalid context at mm/slab.c:2000
Aug 22 09:40:22 localhost kernel: in_atomic():1[expected: 0], 
irqs_disabled():1
Aug 22 09:40:22 localhost kernel:  [<0211b765>] __might_sleep+0x82/0x8c
Aug 22 09:40:22 localhost kernel:  [<021470e7>] __kmalloc+0x42/0x7d
Aug 22 09:40:22 localhost kernel:  [<2188c14e>] 
ohci_urb_enqueue+0x105/0x46c [ohci_hcd]
Aug 22 09:40:22 localhost kernel:  [<02273d60>] hcd_submit_urb+0x205/0x241
Aug 22 09:40:22 localhost kernel:  [<02274b25>] usb_submit_urb+0x1d6/0x1dd
Aug 22 09:40:22 localhost kernel:  [<022746c4>] 
usb_hcd_giveback_urb+0x14/0x3d
Aug 22 09:40:22 localhost kernel:  [<2188af4a>] finish_urb+0x190/0x220 
[ohci_hcd]
Aug 22 09:40:22 localhost kernel:  [<2188bfdb>] dl_done_list+0x4f/0xbd 
[ohci_hcd]
Aug 22 09:40:22 localhost kernel:  [<2188cd16>] ohci_irq+0x131/0x2b6 
[ohci_hcd]
Aug 22 09:40:22 localhost kernel:  [<02274713>] usb_hcd_irq+0x26/0x4b
Aug 22 09:40:22 localhost kernel:  [<0210782f>] handle_IRQ_event+0x21/0x41
Aug 22 09:40:22 localhost kernel:  [<02107d2e>] do_IRQ+0x1be/0x303
Aug 22 09:40:22 localhost kernel:  =======================
Aug 22 09:40:22 localhost kernel:  [<0210403b>] default_idle+0x23/0x26
Aug 22 09:40:22 localhost kernel:  [<0210408c>] cpu_idle+0x1f/0x34
Aug 22 09:40:22 localhost kernel:  [<0239b6ae>] start_kernel+0x221/0x224

However if I use kernel-2.6.6-1.435.2.3 then none of these messages appear.

The system appears to function correctly despite these messages. Does 
anyone have any idea as to their cause and if stability is likely to be 
affected?

Thanks
Dave Hawkes