mips: defconfig: drop RT_GROUP_SCHED=y from generic/db1xxx/eyeq5

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@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

diff --git a/arch/mips/configs/db1xxx_defconfig b/arch/mips/configs/db1xxx_defconfig
index b2d9253ff786fd7ba0e50a9ea9e991d26e05a9cc..6eff21ff15d54194bca2440c833a72b241da03f6 100644 (file)
--- a/arch/mips/configs/db1xxx_defconfig
+++ b/arch/mips/configs/db1xxx_defconfig
@@ -12,7 +12,6 @@ CONFIG_MEMCG=y
 CONFIG_BLK_CGROUP=y
 CONFIG_CGROUP_SCHED=y
 CONFIG_CFS_BANDWIDTH=y
-CONFIG_RT_GROUP_SCHED=y
 CONFIG_CGROUP_FREEZER=y
 CONFIG_CGROUP_DEVICE=y
 CONFIG_CGROUP_CPUACCT=y

diff --git a/arch/mips/configs/eyeq5_defconfig b/arch/mips/configs/eyeq5_defconfig
index c35c29a4d479551a1bf93178ea997589aacbb9fc..3794707c95222e7d2607728e8205d7932cfe6ab7 100644 (file)
--- a/arch/mips/configs/eyeq5_defconfig
+++ b/arch/mips/configs/eyeq5_defconfig
@@ -8,7 +8,6 @@ CONFIG_IKCONFIG_PROC=y
 CONFIG_MEMCG=y
 CONFIG_BLK_CGROUP=y
 CONFIG_CFS_BANDWIDTH=y
-CONFIG_RT_GROUP_SCHED=y
 CONFIG_CGROUP_PIDS=y
 CONFIG_CGROUP_FREEZER=y
 CONFIG_CPUSETS=y

diff --git a/arch/mips/configs/generic_defconfig b/arch/mips/configs/generic_defconfig
index 071e2205c7edef195fea4a2dfd69c4f1a4dd4b70..fa916407bdd44791566091d1e4ac73c4113fcd93 100644 (file)
--- a/arch/mips/configs/generic_defconfig
+++ b/arch/mips/configs/generic_defconfig
@@ -5,7 +5,6 @@ CONFIG_IKCONFIG_PROC=y
 CONFIG_MEMCG=y
 CONFIG_BLK_CGROUP=y
 CONFIG_CFS_BANDWIDTH=y
-CONFIG_RT_GROUP_SCHED=y
 CONFIG_CGROUP_PIDS=y
 CONFIG_CGROUP_FREEZER=y
 CONFIG_CPUSETS=y