From: Christian Goeschel Ndjomouo Date: Sun, 5 Apr 2026 19:14:07 +0000 (-0400) Subject: chrt: (man) explain which kernel config options are needed for SCHED_EXT X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=895ddbf09ea94e9229dbe733f86fb0deb747ebcd;p=thirdparty%2Futil-linux.git chrt: (man) explain which kernel config options are needed for SCHED_EXT On systems running kernel version 6.12+ it is still possible that the syscall to set SCHED_EXT fails with EINVAL, this can happen when certain kernel configuration options have not been set. The list of required options can be found here: https://docs.kernel.org/scheduler/sched-ext.html#switching-to-and-from-sched-ext Let's document this in the man page to give users a heads up. Signed-off-by: Christian Goeschel Ndjomouo --- diff --git a/schedutils/chrt.1.adoc b/schedutils/chrt.1.adoc index ec08fd721..b8d8874bc 100644 --- a/schedutils/chrt.1.adoc +++ b/schedutils/chrt.1.adoc @@ -68,6 +68,7 @@ Set scheduling policy to *SCHED_DEADLINE* (sporadic task model deadline scheduli *-e*, *--ext*:: Set scheduling policy to *SCHED_EXT* (BPF program-defined scheduling). Linux-specific, supported since 6.12. Since util-linux v2.42, the priority argument is optional; if specified, it must be set to zero. +Note that for the policy to be recognized, the following kernel configuration options need to be enabled: *CONFIG_BPF*, *CONFIG_SCHED_CLASS_EXT*, *CONFIG_BPF_SYSCALL*, *CONFIG_BPF_JIT*, *CONFIG_DEBUG_INFO_BTF*, *CONFIG_BPF_JIT_ALWAYS_ON* and *CONFIG_BPF_JIT_DEFAULT_ON*. == SCHEDULING OPTIONS