WARNING: CPU: 2 PID: 207 at drivers/nvme/host/core.c:527 nvme_setup_cmd+0x3d3

[Keith Busch]

On Tue, Jan 30, 2018 at 08:57:49AM -0700, Jens Axboe wrote:
> 
> Looking at the disassembly, 'n' is 2 and 'segments' is 0xffff.

Is this still a problem if you don't use an IO scheduler? With deadline,
I'm not finding any path to bio_attempt_discard_merge which is where the
nr_phys_segments is supposed to get it set to 2. Not sure how it could
becmoe 0xffff, though.