Hi, i just wanted to have a look at RT_GROUP_SCHED as a way to prevent crashing real-time applications from starving other rt application, in the case of prio based scheduling. I had to find out that the feature is not compatible with PREEMPT_RT and quickly traced it down to the following commit: "sched: Disable CONFIG_RT_GROUP_SCHED on RT" https://kernel.googlesource.com/pub/scm/linux/kernel/git/paulg/3.4-rt-patches/+/1b19454df58db731fa9ca09b34909d28d4eef968/patches/0133-sched-Disable-CONFIG_RT_GROUP_SCHED-on-RT.patch My current theory is that there never was a problem with the two not being compatible ... it was more likely a broken userland, more specific a broken cgroups setup. Further my theory is, if you set cgroups up correctly both featues can most likely be combined without a problem ... But maybe i am totally wrong and there are some reasons, in that case the commit should be a little more verbose. And i would be happy to hear about it. On newer systems ... systemd is the reason ... fits the "works in ssh but not in rc.local" https://www.freedesktop.org/wiki/Software/systemd/MyServiceCantGetRealtime/ > Note that this all only applies to services. > ... On older systems it might have been libcgroup/cgconfig like explained here: https://github.com/jackaudio/jackaudio.github.com/wiki/Cgroups http://jackaudio.org/faq/linux_group_sched.html regards, Henning -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
