[08/39] sched: Enumerate CPU cgroup file types

Commit Message

Tejun Heo May 1, 2024, 3:09 p.m. UTC

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 <[e-mail]>
Reviewed-by: David Vernet <[e-mail]>
Acked-by: Josh Don <[e-mail]>
Acked-by: Hao Luo <[e-mail]>
Acked-by: Barret Rhoden <[e-mail]>
---
 kernel/sched/core.c  | 22 +++++++++++-----------
 kernel/sched/sched.h | 21 +++++++++++++++++++++
 2 files changed, 32 insertions(+), 11 deletions(-)

Patch

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 987209c0e672..e48af9fbbd71 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -11196,7 +11196,7 @@  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",
@@ -11425,21 +11425,21 @@  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,
@@ -11447,13 +11447,13 @@  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,
@@ -11461,13 +11461,13 @@  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,
@@ -11488,8 +11488,8 @@  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 7e0de4cb5a52..0b6a34ba2457 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -3505,4 +3505,25 @@  static inline void init_sched_mm_cid(struct task_struct *t) { }
 extern u64 avg_vruntime(struct cfs_rq *cfs_rq);
 extern int entity_eligible(struct cfs_rq *cfs_rq, struct sched_entity *se);
 
+#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 */