From f4e74be1856b3ac058acbf1be321c31d5299f69f Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Sat, 11 Jul 2015 14:18:35 -0300 Subject: [PATCH] README: document that RT group sched should be turned off https://bugs.freedesktop.org/show_bug.cgi?id=87570 https://bugzilla.redhat.com/show_bug.cgi?id=1229700 --- README | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/README b/README index 53220ff3f2..e15fa77dee 100644 --- a/README +++ b/README @@ -82,11 +82,11 @@ REQUIREMENTS: CONFIG_SECCOMP CONFIG_CHECKPOINT_RESTORE (for the kcmp() syscall) - Required for CPUShares in resource control unit settings + Required for CPUShares= in resource control unit settings CONFIG_CGROUP_SCHED CONFIG_FAIR_GROUP_SCHED - Required for CPUQuota in resource control unit settings + Required for CPUQuota= in resource control unit settings CONFIG_CFS_BANDWIDTH For systemd-bootchart, several proc debug interfaces are required: @@ -97,6 +97,15 @@ REQUIREMENTS: CONFIG_EFIVAR_FS CONFIG_EFI_PARTITION + We recommend to turn off Real-Time group scheduling in the + kernel when using systemd. RT group scheduling effectively + makes RT scheduling unavailable for most userspace, since it + requires explicit assignment of RT budgets to each unit whose + processes making use of RT. As there's no sensible way to + assign these budgets automatically this cannot really be + fixed, and it's best to disable group scheduling hence. + CONFIG_RT_GROUP_SCHED=n + Note that kernel auditing is broken when used with systemd's container code. When using systemd in conjunction with containers, please make sure to either turn off auditing at