From: Tejun Heo <tj@kernel.org> mainline inclusion from mainline-v6.16-rc3 commit 33796b91871ad4010c8188372dd1faf97cf0f1c0 category: feature bugzilla: https://atomgit.com/openeuler/kernel/issues/8335 Reference: https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commi... -------------------------------- During task_group creation, sched_create_group() calls scx_group_set_weight() with CGROUP_WEIGHT_DFL to initialize the sched_ext portion. This is premature and ends up calling ops.cgroup_set_weight() with an incorrect @cgrp before ops.cgroup_init() is called. sched_create_group() should just initialize SCX related fields in the new task_group. Fix it by factoring out scx_tg_init() from sched_init() and making sched_create_group() call that function instead of scx_group_set_weight(). v2: Retain CONFIG_EXT_GROUP_SCHED ifdef in sched_init() as removing it leads to build failures on !CONFIG_GROUP_SCHED configs. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: 819513666966 ("sched_ext: Add cgroup support") Cc: stable@vger.kernel.org # v6.12+ Conflicts: kernel/sched/core.c [Conflict with a82fbc2607b0 ("sched: programmable: Add a tag for the task group"), accept both.] Signed-off-by: Zicheng Qu <quzicheng@huawei.com> Signed-off-by: cheliequan <cheliequan@inspur.com> Signed-off-by: Luo Gengkun <luogengkun2@huawei.com> --- kernel/sched/core.c | 4 ++-- kernel/sched/ext.c | 5 +++++ kernel/sched/ext.h | 2 ++ 3 files changed, 9 insertions(+), 2 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 75f2f54f565d..b50746de64c7 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -8346,7 +8346,7 @@ void __init sched_init(void) init_cfs_bandwidth(&root_task_group.cfs_bandwidth, NULL); #endif /* CONFIG_FAIR_GROUP_SCHED */ #ifdef CONFIG_EXT_GROUP_SCHED - root_task_group.scx_weight = CGROUP_WEIGHT_DFL; + scx_tg_init(&root_task_group); #endif /* CONFIG_EXT_GROUP_SCHED */ #ifdef CONFIG_RT_GROUP_SCHED root_task_group.rt_se = (struct sched_rt_entity **)ptr; @@ -8895,7 +8895,7 @@ struct task_group *sched_create_group(struct task_group *parent) tg_init_tag(tg, parent); #endif - scx_group_set_weight(tg, CGROUP_WEIGHT_DFL); + scx_tg_init(tg); alloc_uclamp_sched_group(tg, parent); return tg; diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index a5d661694939..54fc3d6610a8 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -3815,6 +3815,11 @@ static void scx_cgroup_warn_missing_idle(struct task_group *tg) cgroup_warned_missing_idle = true; } +void scx_tg_init(struct task_group *tg) +{ + tg->scx_weight = CGROUP_WEIGHT_DFL; +} + int scx_tg_online(struct task_group *tg) { int ret = 0; diff --git a/kernel/sched/ext.h b/kernel/sched/ext.h index 4c7ffc431c38..70039610bd72 100644 --- a/kernel/sched/ext.h +++ b/kernel/sched/ext.h @@ -91,6 +91,7 @@ static inline void scx_update_idle(struct rq *rq, bool idle, bool do_notify) {} #ifdef CONFIG_CGROUP_SCHED #ifdef CONFIG_EXT_GROUP_SCHED +void scx_tg_init(struct task_group *tg); int scx_tg_online(struct task_group *tg); void scx_tg_offline(struct task_group *tg); int scx_cgroup_can_attach(struct cgroup_taskset *tset); @@ -100,6 +101,7 @@ void scx_cgroup_cancel_attach(struct cgroup_taskset *tset); void scx_group_set_weight(struct task_group *tg, unsigned long cgrp_weight); void scx_group_set_idle(struct task_group *tg, bool idle); #else /* CONFIG_EXT_GROUP_SCHED */ +static inline void scx_tg_init(struct task_group *tg) {} static inline int scx_tg_online(struct task_group *tg) { return 0; } static inline void scx_tg_offline(struct task_group *tg) {} static inline int scx_cgroup_can_attach(struct cgroup_taskset *tset) { return 0; } -- 2.34.1