Public bug reported: Hello,
We've just had a rather length chat in #ubuntu-touch about some problems related to rtkit and pulseaudio on the phone and then on any trusty machine. It turns out that since we now put all users in their own cpu cgroup, rt_runtime_us is set to 0 which prevents any of those tasks from ever getting real-time priority. There are various ways we could try to hack around that in logind, basically manually inheriting a sane value, etc... However it turns out that we never use those cgroup bits and that they are concerned as some kind of security problems when users have access to those. So given that, it seems like the best course of action is just to turn off CONFIG_RT_GROUP_SCHED in all our kernels. This will revert us to a pre-trusty behaviour where users can't set the rt priority but rtkit (a privileged daemon) can, so pulseaudio and the rest of those software should be happy again. ** Affects: linux (Ubuntu) Importance: Undecided Status: New ** Tags: bot-stop-nagging -- 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/1284731 Title: Please turn off CONFIG_RT_GROUP_SCHED in all our kernels Status in “linux” package in Ubuntu: New Bug description: Hello, We've just had a rather length chat in #ubuntu-touch about some problems related to rtkit and pulseaudio on the phone and then on any trusty machine. It turns out that since we now put all users in their own cpu cgroup, rt_runtime_us is set to 0 which prevents any of those tasks from ever getting real-time priority. There are various ways we could try to hack around that in logind, basically manually inheriting a sane value, etc... However it turns out that we never use those cgroup bits and that they are concerned as some kind of security problems when users have access to those. So given that, it seems like the best course of action is just to turn off CONFIG_RT_GROUP_SCHED in all our kernels. This will revert us to a pre-trusty behaviour where users can't set the rt priority but rtkit (a privileged daemon) can, so pulseaudio and the rest of those software should be happy again. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1284731/+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