[PATCH 09/30] sched: Enumerate CPU cgroup file types

Tejun Heo
2023-01-28T00:17:56Z

Rename cpu[_legacy]_files to cpu[_legacy]_cftypes for clarity and add
cpu_cftype_id which enumerates every cgroup2 interface file type. This
doesn't make any functional difference now. The enums will be used to access
specific cftypes by a new BPF extensible sched_class to selectively show and
hide CPU controller interface files depending on the capability of the
currently loaded BPF scheduler progs.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: David Vernet <dvernet@meta.com>
Acked-by: Josh Don <joshdon@google.com>
Acked-by: Hao Luo <haoluo@google.com>
Acked-by: Barret Rhoden <brho@google.com>
---
kernel/sched/core.c | 22 +++++++++++-----------
kernel/sched/sched.h | 21 +++++++++++++++++++++
2 files changed, 32 insertions(+), 11 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 1fd4e2cde35c..729de63ee6ec 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -10941,7 +10941,7 @@ static int cpu_idle_write_s64(struct cgroup_subsys_state *css,
}
#endif

-static struct cftype cpu_legacy_files[] = {
+static struct cftype cpu_legacy_cftypes[] = {
#ifdef CONFIG_FAIR_GROUP_SCHED
{
.name = "shares",
@@ -11148,21 +11148,21 @@ static ssize_t cpu_max_write(struct kernfs_open_file *of,
}
#endif

-static struct cftype cpu_files[] = {
+struct cftype cpu_cftypes[CPU_CFTYPE_CNT + 1] = {
#ifdef CONFIG_FAIR_GROUP_SCHED
- {
+ [CPU_CFTYPE_WEIGHT] = {
.name = "weight",
.flags = CFTYPE_NOT_ON_ROOT,
.read_u64 = cpu_weight_read_u64,
.write_u64 = cpu_weight_write_u64,
},
- {
+ [CPU_CFTYPE_WEIGHT_NICE] = {
.name = "weight.nice",
.flags = CFTYPE_NOT_ON_ROOT,
.read_s64 = cpu_weight_nice_read_s64,
.write_s64 = cpu_weight_nice_write_s64,
},
- {
+ [CPU_CFTYPE_IDLE] = {
.name = "idle",
.flags = CFTYPE_NOT_ON_ROOT,
.read_s64 = cpu_idle_read_s64,
@@ -11170,13 +11170,13 @@ static struct cftype cpu_files[] = {
},
#endif
#ifdef CONFIG_CFS_BANDWIDTH
- {
+ [CPU_CFTYPE_MAX] = {
.name = "max",
.flags = CFTYPE_NOT_ON_ROOT,
.seq_show = cpu_max_show,
.write = cpu_max_write,
},
- {
+ [CPU_CFTYPE_MAX_BURST] = {
.name = "max.burst",
.flags = CFTYPE_NOT_ON_ROOT,
.read_u64 = cpu_cfs_burst_read_u64,
@@ -11184,13 +11184,13 @@ static struct cftype cpu_files[] = {
},
#endif
#ifdef CONFIG_UCLAMP_TASK_GROUP
- {
+ [CPU_CFTYPE_UCLAMP_MIN] = {
.name = "uclamp.min",
.flags = CFTYPE_NOT_ON_ROOT,
.seq_show = cpu_uclamp_min_show,
.write = cpu_uclamp_min_write,
},
- {
+ [CPU_CFTYPE_UCLAMP_MAX] = {
.name = "uclamp.max",
.flags = CFTYPE_NOT_ON_ROOT,
.seq_show = cpu_uclamp_max_show,
@@ -11210,8 +11210,8 @@ struct cgroup_subsys cpu_cgrp_subsys = {
.can_attach = cpu_cgroup_can_attach,
#endif
.attach = cpu_cgroup_attach,
- .legacy_cftypes = cpu_legacy_files,
- .dfl_cftypes = cpu_files,
+ .legacy_cftypes = cpu_legacy_cftypes,
+ .dfl_cftypes = cpu_cftypes,
.early_init = true,
.threaded = true,
};
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 1927adc6c4bb..dd567eb7881a 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -3334,4 +3334,25 @@ static inline void update_current_exec_runtime(struct task_struct *curr,
cgroup_account_cputime(curr, delta_exec);
}

+#ifdef CONFIG_CGROUP_SCHED
+enum cpu_cftype_id {
+#ifdef CONFIG_FAIR_GROUP_SCHED
+ CPU_CFTYPE_WEIGHT,
+ CPU_CFTYPE_WEIGHT_NICE,
+ CPU_CFTYPE_IDLE,
+#endif
+#ifdef CONFIG_CFS_BANDWIDTH
+ CPU_CFTYPE_MAX,
+ CPU_CFTYPE_MAX_BURST,
+#endif
+#ifdef CONFIG_UCLAMP_TASK_GROUP
+ CPU_CFTYPE_UCLAMP_MIN,
+ CPU_CFTYPE_UCLAMP_MAX,
+#endif
+ CPU_CFTYPE_CNT,
+};
+
+extern struct cftype cpu_cftypes[CPU_CFTYPE_CNT + 1];
+#endif /* CONFIG_CGROUP_SCHED */
+
#endif /* _KERNEL_SCHED_SCHED_H */
--
2.39.1