diff options
| author | Michal Koutný <mkoutny@suse.com> | 2025-03-10 18:04:36 +0100 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2025-04-08 20:55:53 +0200 |
| commit | e34e0131fea1b0f63c2105a1958c94af2ee90f4d (patch) | |
| tree | 4fa9cdf6052340a717e6e991aa86023d47ac0036 | |
| parent | a5a25b32c08a31c03258ec4960bec26caaf76e9a (diff) | |
sched: Add commadline option for RT_GROUP_SCHED toggling
Only simple implementation with a static key wrapper, it will be wired
in later.
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250310170442.504716-5-mkoutny@suse.com
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 5 | ||||
| -rw-r--r-- | init/Kconfig | 11 | ||||
| -rw-r--r-- | kernel/sched/core.c | 25 | ||||
| -rw-r--r-- | kernel/sched/sched.h | 17 |
4 files changed, 58 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 3f35d5b8c296..168202330cfa 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -6280,6 +6280,11 @@ Memory area to be used by remote processor image, managed by CMA. + rt_group_sched= [KNL] Enable or disable SCHED_RR/FIFO group scheduling + when CONFIG_RT_GROUP_SCHED=y. Defaults to + !CONFIG_RT_GROUP_SCHED_DEFAULT_DISABLED. + Format: <bool> + rw [KNL] Mount root device read-write on boot S [KNL] Run init in single mode diff --git a/init/Kconfig b/init/Kconfig index 681f38ee68db..b2c045c71d7f 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1082,6 +1082,17 @@ config RT_GROUP_SCHED realtime bandwidth for them. See Documentation/scheduler/sched-rt-group.rst for more information. +config RT_GROUP_SCHED_DEFAULT_DISABLED + bool "Require boot parameter to enable group scheduling for SCHED_RR/FIFO" + depends on RT_GROUP_SCHED + default n + help + When set, the RT group scheduling is disabled by default. The option + is in inverted form so that mere RT_GROUP_SCHED enables the group + scheduling. + + Say N if unsure. + config EXT_GROUP_SCHED bool depends on SCHED_CLASS_EXT && CGROUP_SCHED diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 042c978f7c9b..58d093a8c1af 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -9892,6 +9892,31 @@ static struct cftype cpu_legacy_files[] = { { } /* Terminate */ }; +#ifdef CONFIG_RT_GROUP_SCHED +# ifdef CONFIG_RT_GROUP_SCHED_DEFAULT_DISABLED +DEFINE_STATIC_KEY_FALSE(rt_group_sched); +# else +DEFINE_STATIC_KEY_TRUE(rt_group_sched); +# endif + +static int __init setup_rt_group_sched(char *str) +{ + long val; + + if (kstrtol(str, 0, &val) || val < 0 || val > 1) { + pr_warn("Unable to set rt_group_sched\n"); + return 1; + } + if (val) + static_branch_enable(&rt_group_sched); + else + static_branch_disable(&rt_group_sched); + + return 1; +} +__setup("rt_group_sched=", setup_rt_group_sched); +#endif /* CONFIG_RT_GROUP_SCHED */ + static int cpu_extra_stat_show(struct seq_file *sf, struct cgroup_subsys_state *css) { diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index c006348102d9..d1e591f91cf8 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1500,6 +1500,23 @@ static inline bool sched_group_cookie_match(struct rq *rq, } #endif /* !CONFIG_SCHED_CORE */ +#ifdef CONFIG_RT_GROUP_SCHED +# ifdef CONFIG_RT_GROUP_SCHED_DEFAULT_DISABLED +DECLARE_STATIC_KEY_FALSE(rt_group_sched); +static inline bool rt_group_sched_enabled(void) +{ + return static_branch_unlikely(&rt_group_sched); +} +# else +DECLARE_STATIC_KEY_TRUE(rt_group_sched); +static inline bool rt_group_sched_enabled(void) +{ + return static_branch_likely(&rt_group_sched); +} +# endif /* CONFIG_RT_GROUP_SCHED_DEFAULT_DISABLED */ +#else +# define rt_group_sched_enabled() false +#endif /* CONFIG_RT_GROUP_SCHED */ static inline void lockdep_assert_rq_held(struct rq *rq) { |