On Tue, 2018-03-13 at 19:16 +0200, Jaco Kroon wrote: > The server in question is the destination of numerous rsync/ssh cases > (used primarily for backups) and is not intended as a real-time system. > I'm happy to enable the options below that you would indicate would be > helpful in pinpointing the problem (assuming we're not looking at a 8x > more CPU required type of degrading as I've recently seen with asterisk > lock debugging enabled). I've marked in bold below what I assume would > be helpful. If you don't mind confirming for me I'll enable and > schedule a reboot. Hello Jaco, My recommendation is to wait until the mpt3sas maintainers post a fix for what I reported yesterday on the linux-scsi mailing list. Enabling CONFIG_DEBUG_ATOMIC_SLEEP has namely a very annoying consequence for the mpt3sas driver: the first process that hits the "sleep in atomic context" bug gets killed. I don't think that you want this kind of behavior on a production setup. Bart.