From b01e55f701062f77ddd5788de4c0e0183e6f964e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E5=BF=98=E6=80=80?= Date: Tue, 4 Jun 2024 07:10:43 +0000 Subject: [PATCH] arm64: defconfig: drop RT_GROUP_SCHED=y from deepin_arm64_desktop_defconfig 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] I leave tools/testing/selftests/bpf/config.{s390x,aarch64} untouched because I don't whether bpf testing requires it. [1]: https://bugzilla.redhat.com/show_bug.cgi?id=1229700 [2]: https://github.com/systemd/systemd/issues/13781#issuecomment-549164383 Change-Id: I079a907dfba15bb48c58a39aba3b4f4e283b37fc Signed-off-by: Celeste Liu Signed-off-by: Wentao Guan --- arch/arm64/configs/deepin_arm64_desktop_defconfig | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/arm64/configs/deepin_arm64_desktop_defconfig b/arch/arm64/configs/deepin_arm64_desktop_defconfig index ac880cf66f2a1..2e9538807e285 100644 --- a/arch/arm64/configs/deepin_arm64_desktop_defconfig +++ b/arch/arm64/configs/deepin_arm64_desktop_defconfig @@ -21,7 +21,6 @@ CONFIG_UCLAMP_TASK=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