On 04/05/12 13:58, Tomas Henzl wrote: > When a rmmod is tried then in some cases the kernel is not able to handle a paging request: > [ 727.154296] BUG: unable to handle kernel paging request at ffffffffa01874b8 > From what I observerved it happens when when we call the rmmod only a while after a modprobe > (in this case it is the mpt2sas driver). More accurately said, it happens when rmmod is called > while scsi async is still at work. The driver is removed but the scsi_host_template is still filled > with now invalid pointers, in this case it is most likely the hostt->scan_finished which causes the BUG. Are you sure the above analysis is correct ? I've triggered several million device removal events with ib_srp but I haven't ever seen the above crash. Maybe your patch for the SCSI core is hiding a race in the mpt2sas device removal code. Bart. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html