This bug was fixed in the package linux - 5.4.0-26.30 --------------- linux (5.4.0-26.30) focal; urgency=medium
* focal/linux: 5.4.0-26.30 -proposed tracker (LP: #1873882) * Packaging resync (LP: #1786013) - update dkms package versions * swap storms kills interactive use (LP: #1861359) - SAUCE: drm/i915: prevent direct writeback from the shrinker * 5.4.0-24.28 does not seem to apply rtprio, whereas -21 does. (LP: #1873315) - [Config] lowlatency: turn off RT_GROUP_SCHED * [RTL810xE] No ethernet connection (LP: #1871182) - net: phy: realtek: fix handling of RTL8105e-integrated PHY -- Andrea Righi <andrea.ri...@canonical.com> Mon, 20 Apr 2020 18:33:49 +0200 ** Changed in: linux (Ubuntu) Status: Fix Committed => Fix Released -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1873315 Title: 5.4.0-24.28 does not seem to apply rtprio, whereas -21 does. Status in linux package in Ubuntu: Fix Released Bug description: 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 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) and encourage people to use -lowlatency if they hit this problem. 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. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1873315/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp