** Description changed: + Impact: + + Software that requires RT priority is not working anymore since we + turned on RT_GROUP_SCHED: + + commit 9b039fc517876d312e7fa0955571101a299c91f5 + Author: Seth Forshee <seth.fors...@canonical.com> + Date: Mon Apr 6 07:11:44 2020 -0500 + + UBUNTU: [Config] CONFIG_RT_GROUP_SCHED=y + + This is wanted by docker, and the original reason for disabling + it no longer applied. Performance testing shows no noticible + impact when the option is enabled. + + + We already his this issue in the past (see https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1284731), but nowadays reverting RT_GROUP_SCHED back to off would regress Docker and since RT privileges are usually required by audio/multimedia software, it probably make sense to revert this change only for -lowlatency, and keep the rest as is. + + Fix: + + Apply the attached patch + + Regression potential: + + None, only -lowlatency is impacted, -generic doesn't change. + + -- + + I'm using the xwax package on a Dell XPS 13 (9370) 20.04, which requires rtprio privileges: - [daniel@reef ~ ]$ sudo cat /etc/security/limits.d/audio.conf + [daniel@reef ~ ]$ sudo cat /etc/security/limits.d/audio.conf @audio - rtprio 99 [daniel@reef ~ ]$ This worked fine for the past releases of Ubuntu up until the move from linux-image-5.4.0-21-generic to linux-image-5.4.0-24-generic. Today I'm seeing: Launching realtime thread to handle devices... sched_setscheduler: Operation not permitted Failed to get realtime priorities Booting the previous kernel makes it work. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: linux-image-5.4.0-24-generic 5.4.0-24.28 ProcVersionSignature: Ubuntu 5.4.0-24.28-generic 5.4.30 Uname: Linux 5.4.0-24-generic x86_64 ApportVersion: 2.20.11-0ubuntu27 Architecture: amd64 AudioDevicesInUse: - USER PID ACCESS COMMAND - /dev/snd/controlC0: daniel 2905 F.... pulseaudio + USER PID ACCESS COMMAND + /dev/snd/controlC0: daniel 2905 F.... pulseaudio CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME Date: Thu Apr 16 18:57:21 2020 InstallationDate: Installed on 2018-04-14 (733 days ago) InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Alpha amd64 (20180409) Lsusb: - Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub - Bus 001 Device 003: ID 0489:e0a2 Foxconn / Hon Hai - Bus 001 Device 002: ID 0bda:58f4 Realtek Semiconductor Corp. Integrated_Webcam_HD - Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub + Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub + Bus 001 Device 003: ID 0489:e0a2 Foxconn / Hon Hai + Bus 001 Device 002: ID 0bda:58f4 Realtek Semiconductor Corp. Integrated_Webcam_HD + Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub MachineType: Dell Inc. XPS 13 9370 ProcFB: 0 i915drmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-24-generic root=UUID=0af0a12d-3b1e-4708-89c4-73f666ddc618 ro quiet splash vt.handoff=7 RelatedPackageVersions: - linux-restricted-modules-5.4.0-24-generic N/A - linux-backports-modules-5.4.0-24-generic N/A - linux-firmware 1.187 + linux-restricted-modules-5.4.0-24-generic N/A + linux-backports-modules-5.4.0-24-generic N/A + linux-firmware 1.187 SourcePackage: linux UpgradeStatus: Upgraded to focal on 2020-03-08 (39 days ago) dmi.bios.date: 02/21/2018 dmi.bios.vendor: Dell Inc. dmi.bios.version: 1.2.1 dmi.board.name: 0F6P3V dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 9 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvr1.2.1:bd02/21/2018:svnDellInc.:pnXPS139370:pvr:rvnDellInc.:rn0F6P3V:rvrA00:cvnDellInc.:ct9:cvr: dmi.product.family: XPS dmi.product.name: XPS 13 9370 dmi.product.sku: 07E6 dmi.sys.vendor: Dell Inc.
** Patch added: "0001-UBUNTU-Config-lowlatency-turn-off-RT_GROUP_SCHED.patch" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1873315/+attachment/5356084/+files/0001-UBUNTU-Config-lowlatency-turn-off-RT_GROUP_SCHED.patch ** Description changed: Impact: Software that requires RT priority is not working anymore since we turned on RT_GROUP_SCHED: commit 9b039fc517876d312e7fa0955571101a299c91f5 Author: Seth Forshee <seth.fors...@canonical.com> Date: Mon Apr 6 07:11:44 2020 -0500 UBUNTU: [Config] CONFIG_RT_GROUP_SCHED=y - + This is wanted by docker, and the original reason for disabling it no longer applied. Performance testing shows no noticible impact when the option is enabled. - - We already his this issue in the past (see https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1284731), but nowadays reverting RT_GROUP_SCHED back to off would regress Docker and since RT privileges are usually required by audio/multimedia software, it probably make sense to revert this change only for -lowlatency, and keep the rest as is. + We already had this issue in the past (see + https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1284731), but + nowadays reverting RT_GROUP_SCHED back to off would regress Docker and + since RT privileges are usually required by audio/multimedia software, + it probably make sense to revert this change only for -lowlatency, and + keep the rest as is. Fix: Apply the attached patch Regression potential: None, only -lowlatency is impacted, -generic doesn't change. -- - I'm using the xwax package on a Dell XPS 13 (9370) 20.04, which requires rtprio privileges: [daniel@reef ~ ]$ sudo cat /etc/security/limits.d/audio.conf @audio - rtprio 99 [daniel@reef ~ ]$ This worked fine for the past releases of Ubuntu up until the move from linux-image-5.4.0-21-generic to linux-image-5.4.0-24-generic. Today I'm seeing: Launching realtime thread to handle devices... sched_setscheduler: Operation not permitted Failed to get realtime priorities Booting the previous kernel makes it work. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: linux-image-5.4.0-24-generic 5.4.0-24.28 ProcVersionSignature: Ubuntu 5.4.0-24.28-generic 5.4.30 Uname: Linux 5.4.0-24-generic x86_64 ApportVersion: 2.20.11-0ubuntu27 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: daniel 2905 F.... pulseaudio CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME Date: Thu Apr 16 18:57:21 2020 InstallationDate: Installed on 2018-04-14 (733 days ago) InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Alpha amd64 (20180409) Lsusb: Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 001 Device 003: ID 0489:e0a2 Foxconn / Hon Hai Bus 001 Device 002: ID 0bda:58f4 Realtek Semiconductor Corp. Integrated_Webcam_HD Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub MachineType: Dell Inc. XPS 13 9370 ProcFB: 0 i915drmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-24-generic root=UUID=0af0a12d-3b1e-4708-89c4-73f666ddc618 ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-5.4.0-24-generic N/A linux-backports-modules-5.4.0-24-generic N/A linux-firmware 1.187 SourcePackage: linux UpgradeStatus: Upgraded to focal on 2020-03-08 (39 days ago) dmi.bios.date: 02/21/2018 dmi.bios.vendor: Dell Inc. dmi.bios.version: 1.2.1 dmi.board.name: 0F6P3V dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 9 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvr1.2.1:bd02/21/2018:svnDellInc.:pnXPS139370:pvr:rvnDellInc.:rn0F6P3V:rvrA00:cvnDellInc.:ct9:cvr: dmi.product.family: XPS dmi.product.name: XPS 13 9370 dmi.product.sku: 07E6 dmi.sys.vendor: Dell Inc. ** Description changed: Impact: Software that requires RT priority is not working anymore since we turned on RT_GROUP_SCHED: commit 9b039fc517876d312e7fa0955571101a299c91f5 Author: Seth Forshee <seth.fors...@canonical.com> Date: Mon Apr 6 07:11:44 2020 -0500 UBUNTU: [Config] CONFIG_RT_GROUP_SCHED=y This is wanted by docker, and the original reason for disabling it no longer applied. Performance testing shows no noticible impact when the option is enabled. - We already had this issue in the past (see + We already hit this issue in the past (see https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1284731), but nowadays reverting RT_GROUP_SCHED back to off would regress Docker and since RT privileges are usually required by audio/multimedia software, it probably make sense to revert this change only for -lowlatency, and keep the rest as is. Fix: Apply the attached patch Regression potential: None, only -lowlatency is impacted, -generic doesn't change. -- I'm using the xwax package on a Dell XPS 13 (9370) 20.04, which requires rtprio privileges: [daniel@reef ~ ]$ sudo cat /etc/security/limits.d/audio.conf @audio - rtprio 99 [daniel@reef ~ ]$ This worked fine for the past releases of Ubuntu up until the move from linux-image-5.4.0-21-generic to linux-image-5.4.0-24-generic. Today I'm seeing: Launching realtime thread to handle devices... sched_setscheduler: Operation not permitted Failed to get realtime priorities Booting the previous kernel makes it work. ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: linux-image-5.4.0-24-generic 5.4.0-24.28 ProcVersionSignature: Ubuntu 5.4.0-24.28-generic 5.4.30 Uname: Linux 5.4.0-24-generic x86_64 ApportVersion: 2.20.11-0ubuntu27 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: daniel 2905 F.... pulseaudio CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME Date: Thu Apr 16 18:57:21 2020 InstallationDate: Installed on 2018-04-14 (733 days ago) InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Alpha amd64 (20180409) Lsusb: Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 001 Device 003: ID 0489:e0a2 Foxconn / Hon Hai Bus 001 Device 002: ID 0bda:58f4 Realtek Semiconductor Corp. Integrated_Webcam_HD Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub MachineType: Dell Inc. XPS 13 9370 ProcFB: 0 i915drmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-24-generic root=UUID=0af0a12d-3b1e-4708-89c4-73f666ddc618 ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-5.4.0-24-generic N/A linux-backports-modules-5.4.0-24-generic N/A linux-firmware 1.187 SourcePackage: linux UpgradeStatus: Upgraded to focal on 2020-03-08 (39 days ago) dmi.bios.date: 02/21/2018 dmi.bios.vendor: Dell Inc. dmi.bios.version: 1.2.1 dmi.board.name: 0F6P3V dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 9 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvr1.2.1:bd02/21/2018:svnDellInc.:pnXPS139370:pvr:rvnDellInc.:rn0F6P3V:rvrA00:cvnDellInc.:ct9:cvr: dmi.product.family: XPS dmi.product.name: XPS 13 9370 dmi.product.sku: 07E6 dmi.sys.vendor: Dell Inc. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1873315 Title: 5.4.0-24.28 does not seem to apply rtprio, whereas -21 does. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1873315/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
