[Bug 1801305] Re: Restore request-based mode to xen-blkfront for AWS kernels
Ubuntu 18.10 (Cosmic Cuttlefish) has reached end of life, so this bug will not be fixed for that specific release. ** Changed in: linux (Ubuntu Cosmic) Status: Fix Committed => Won't Fix -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1801305 Title: Restore request-based mode to xen-blkfront for AWS kernels To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-aws/+bug/1801305/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1801305] Re: Restore request-based mode to xen-blkfront for AWS kernels
** Changed in: linux (Ubuntu Disco) Status: Triaged => Won't Fix -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1801305 Title: Restore request-based mode to xen-blkfront for AWS kernels To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-aws/+bug/1801305/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1801305] Re: Restore request-based mode to xen-blkfront for AWS kernels
Upon closer inspection, it looks like we probably do want to keep the PM patches, so I've only dropped "UBUNTU: SAUCE: xen-blkfront: resurrect request-based mode." -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1801305 Title: Restore request-based mode to xen-blkfront for AWS kernels To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-aws/+bug/1801305/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1801305] Re: Restore request-based mode to xen-blkfront for AWS kernels
Adding a note that we must drop these patches for 5.0 (disco). The single queue IO schedulers are gone; blk-mq is the only game in town. For reference, this seems to be one of the key commits: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a1ce35fa49852db60fc6e268038530be533c5b15 I don't know if some of the patches are still useful or not. I'm going to drop them all; we can add some of them back if still needed. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1801305 Title: Restore request-based mode to xen-blkfront for AWS kernels To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-aws/+bug/1801305/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1801305] Re: Restore request-based mode to xen-blkfront for AWS kernels
** Also affects: linux-aws (Ubuntu) Importance: Undecided Status: New ** No longer affects: linux (Ubuntu) ** Changed in: linux-aws (Ubuntu Trusty) Status: New => Fix Released ** Changed in: linux-aws (Ubuntu Xenial) Status: New => Fix Released ** Changed in: linux-aws (Ubuntu Bionic) Status: New => Fix Released ** Changed in: linux-aws (Ubuntu Cosmic) Status: New => Fix Released ** Changed in: linux-aws (Ubuntu Disco) Status: New => Fix Released -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1801305 Title: Restore request-based mode to xen-blkfront for AWS kernels To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-aws/+bug/1801305/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1801305] Re: Restore request-based mode to xen-blkfront for AWS kernels
I've checked that the proposed Xenial AWS kernel works - it boots successfully and uses the deadline scheduler by default on a t2.micro instance. Regards, Daniel -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1801305 Title: Restore request-based mode to xen-blkfront for AWS kernels To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1801305/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1801305] Re: Restore request-based mode to xen-blkfront for AWS kernels
** Changed in: linux (Ubuntu Trusty) Status: In Progress => Fix Committed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1801305 Title: Restore request-based mode to xen-blkfront for AWS kernels To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1801305/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1801305] Re: Restore request-based mode to xen-blkfront for AWS kernels
** Also affects: linux (Ubuntu Trusty) Importance: Undecided Status: New ** Also affects: linux (Ubuntu Disco) Importance: Undecided Status: Fix Committed ** Also affects: linux (Ubuntu Xenial) Importance: Undecided Status: New ** Also affects: linux (Ubuntu Bionic) Importance: Undecided Status: New ** Also affects: linux (Ubuntu Cosmic) Importance: Undecided Status: New ** Changed in: linux (Ubuntu Disco) Status: Fix Committed => Triaged ** Changed in: linux (Ubuntu Cosmic) Status: New => Fix Committed ** Changed in: linux (Ubuntu Bionic) Status: New => Fix Committed ** Changed in: linux (Ubuntu Xenial) Status: New => Fix Committed ** Changed in: linux (Ubuntu Trusty) Status: New => In Progress -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1801305 Title: Restore request-based mode to xen-blkfront for AWS kernels To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1801305/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1801305] Re: Restore request-based mode to xen-blkfront for AWS kernels
** Changed in: linux (Ubuntu) Status: Confirmed => Fix Committed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1801305 Title: Restore request-based mode to xen-blkfront for AWS kernels To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1801305/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1801305] Re: Restore request-based mode to xen-blkfront for AWS kernels
** Description changed: In current Ubuntu kernels, PV blkfront drivers have blk-mq enabled by default and cannot use the old I/O scheduler. [Impact] blk-mq is not as fast as the old request-based scheduler for some workloads on HDD disks. [Fix] Amazon Linux has a commit which reintroduces the request-based mode. It disables blk-mq by default but allows it to be switched back on with a kernel parameter. + For B/C this patchset is bigger as it includes the suspend/resume + patches already in X, and a new fixup. These are desirable as the + request mode patch assumes their presence. + [Regression Potential] - Could potentially break xen based disks on AWS. For B/C, the patches also add some code to the xen core around suspend and resume, this code is much smaller and also mirrors code already in Xenial. + Could potentially break xen based disks on AWS. + + For B/C, the patches also add some code to the xen core around suspend + and resume, this code is much smaller and also mirrors code already in + Xenial. [Tests] Tested by AWS for Xenial, and their kernel engineers vetted the patches. I tested the Bionic and Cosmic patchsets with fio, the system appears stable and the IOPS promised for EBS Provisioned IOPS disks were met in my testing. I did an apt update/upgrade and everything worked (no hash-sum mismatches). ** Description changed: In current Ubuntu kernels, PV blkfront drivers have blk-mq enabled by default and cannot use the old I/O scheduler. [Impact] blk-mq is not as fast as the old request-based scheduler for some workloads on HDD disks. [Fix] Amazon Linux has a commit which reintroduces the request-based mode. It disables blk-mq by default but allows it to be switched back on with a kernel parameter. + For X this needs a small patch from upstream for error handling. + For B/C this patchset is bigger as it includes the suspend/resume patches already in X, and a new fixup. These are desirable as the request mode patch assumes their presence. [Regression Potential] - Could potentially break xen based disks on AWS. + Could potentially break xen based disks on AWS. For B/C, the patches also add some code to the xen core around suspend and resume, this code is much smaller and also mirrors code already in Xenial. [Tests] Tested by AWS for Xenial, and their kernel engineers vetted the patches. I tested the Bionic and Cosmic patchsets with fio, the system appears stable and the IOPS promised for EBS Provisioned IOPS disks were met in my testing. I did an apt update/upgrade and everything worked (no hash-sum mismatches). -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1801305 Title: Restore request-based mode to xen-blkfront for AWS kernels To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1801305/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs