On Thu, 2024-05-30 at 19:19 +0800, Celeste Liu wrote: > For cgroup v1, if turned on, and there's any cgroup in the "cpu" hierarchy it > needs an RT budget assigned, otherwise the processes in it will not be able to > get RT at all. The problem with RT group scheduling is that it requires the > budget assigned but there's no way we could assign a default budget, since the > values to assign are both upper and lower time limits, are absolute, and need to > be sum up to < 1 for each individal cgroup. That means we cannot really come up > with values that would work by default in the general case.[1] > > For cgroup v2, it's almost unusable as well. If it turned on, the cpu controller > can only be enabled when all RT processes are in the root cgroup. But it will > lose the benefits of cgroup v2 if all RT process were placed in the same cgroup. > > Red Hat, Gentoo, Arch Linux and Debian all disable it. systemd also doesn't > support it.[2] > > [1]: https://bugzilla.redhat.com/show_bug.cgi?id=1229700 > [2]: https://github.com/systemd/systemd/issues/13781#issuecomment-549164383 > > Signed-off-by: Celeste Liu <CoelacanthusHex@xxxxxxxxx> As a distro maintainer who had once been bitten by this option: Reviewed-by: Xi Ruoyao <xry111@xxxxxxxxxxx> > --- > arch/loongarch/configs/loongson3_defconfig | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/arch/loongarch/configs/loongson3_defconfig b/arch/loongarch/configs/loongson3_defconfig > index b4252c357c8e..4d93adb3f1a2 100644 > --- a/arch/loongarch/configs/loongson3_defconfig > +++ b/arch/loongarch/configs/loongson3_defconfig > @@ -23,7 +23,6 @@ CONFIG_NUMA_BALANCING=y > CONFIG_MEMCG=y > CONFIG_BLK_CGROUP=y > CONFIG_CFS_BANDWIDTH=y > -CONFIG_RT_GROUP_SCHED=y > CONFIG_CGROUP_PIDS=y > CONFIG_CGROUP_RDMA=y > CONFIG_CGROUP_FREEZER=y -- Xi Ruoyao <xry111@xxxxxxxxxxx> School of Aerospace Science and Technology, Xidian University
