I've rolled three patches into a test kernel to test. I believe the best fix is probably "cfq: Disable writeback throttling by default" https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=142bbdfccc8b3e9f7342f2ce8422e76a3b45beae
The commits are: 4d608baac5f4e72b033a122b2d6d9499532c3afc "block: Initialize cfqq->ioprio_class in cfq_get_queue()" 142bbdfccc8b3e9f7342f2ce8422e76a3b45beae "cfq: Disable writeback throttling by default" 5be6b75610cefd1e21b98a218211922c2feb6e08 "cfq-iosched: fix the delay of cfq_group's vdisktime under iops mode" You can download the packages from: http://kernel.ubuntu.com/~cking/lp1709889/ Let me know if this helps with the issue. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1709889 Title: Ubuntu 17.04: Bug in cfq scheduler, I/Os do not get submitted to adapter for a very long time. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-power-systems/+bug/1709889/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
