On Wed, 2017-02-01 at 09:13 -0800, Jens Axboe wrote: > So that's changing the elevator - did this happen while heavy IO was > going to the drive, or was it idle? I just ran into an I/O hang while running test 02-sq on top of kernel v4.9.6. I will have a closer look at the dm code to see whether I can find anything that is wrong in the dm code. Bart.-- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html