From 433bce5dadb4ec3d5eda99c5125926c045b79005 Mon Sep 17 00:00:00 2001 From: Michal Koutný Date: Mon, 10 Mar 2025 18:04:33 +0100 Subject: sched: Convert CONFIG_RT_GROUP_SCHED macros to code conditions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Convert the blocks guarded by macros to regular code so that the RT group code gets more compile validation. Reasoning is in Documentation/process/coding-style.rst 21) Conditional Compilation. With that, no functional change is expected. Signed-off-by: Michal Koutný Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20250310170442.504716-2-mkoutny@suse.com --- kernel/sched/syscalls.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/sched/syscalls.c') diff --git a/kernel/sched/syscalls.c b/kernel/sched/syscalls.c index c326de1344fb..2bf528116fad 100644 --- a/kernel/sched/syscalls.c +++ b/kernel/sched/syscalls.c @@ -640,7 +640,7 @@ change: retval = -EPERM; goto unlock; } -#endif +#endif /* CONFIG_RT_GROUP_SCHED */ #ifdef CONFIG_SMP if (dl_bandwidth_enabled() && dl_policy(policy) && !(attr->sched_flags & SCHED_FLAG_SUGOV)) { -- cgit v1.2.3 From 277e0909754e9f3c82def97150d2f3ea700098f1 Mon Sep 17 00:00:00 2001 From: Michal Koutný Date: Mon, 10 Mar 2025 18:04:38 +0100 Subject: sched: Bypass bandwitdh checks with runtime disabled RT_GROUP_SCHED MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When RT_GROUPs are compiled but not exposed, their bandwidth cannot be configured (and it is not initialized for non-root task_groups neither). Therefore bypass any checks of task vs task_group bandwidth. This will achieve behavior very similar to setups that have !CONFIG_RT_GROUP_SCHED and attach cpu controller to cgroup v2 hierarchy. (On a related note, this may allow having RT tasks with CONFIG_RT_GROUP_SCHED and cgroup v2 hierarchy.) Signed-off-by: Michal Koutný Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20250310170442.504716-7-mkoutny@suse.com --- kernel/sched/core.c | 6 +++++- kernel/sched/rt.c | 2 +- kernel/sched/syscalls.c | 3 ++- 3 files changed, 8 insertions(+), 3 deletions(-) (limited to 'kernel/sched/syscalls.c') diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 32fb4c1100cb..6900ce5b9039 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -9206,11 +9206,15 @@ static int cpu_cgroup_can_attach(struct cgroup_taskset *tset) struct task_struct *task; struct cgroup_subsys_state *css; + if (!rt_group_sched_enabled()) + goto scx_check; + cgroup_taskset_for_each(task, css, tset) { if (!sched_rt_can_attach(css_tg(css), task)) return -EINVAL; } -#endif +scx_check: +#endif /* CONFIG_RT_GROUP_SCHED */ return scx_cgroup_can_attach(tset); } diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index efa22bad31e1..5e82bfe56fdf 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -2864,7 +2864,7 @@ static int sched_rt_global_constraints(void) int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) { /* Don't accept real-time tasks when there is no way for them to run */ - if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) + if (rt_group_sched_enabled() && rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) return 0; return 1; diff --git a/kernel/sched/syscalls.c b/kernel/sched/syscalls.c index 2bf528116fad..547c1f05b667 100644 --- a/kernel/sched/syscalls.c +++ b/kernel/sched/syscalls.c @@ -634,7 +634,8 @@ change: * Do not allow real-time tasks into groups that have no runtime * assigned. */ - if (rt_bandwidth_enabled() && rt_policy(policy) && + if (rt_group_sched_enabled() && + rt_bandwidth_enabled() && rt_policy(policy) && task_group(p)->rt_bandwidth.rt_runtime == 0 && !task_group_is_autogroup(task_group(p))) { retval = -EPERM; -- cgit v1.2.3