* [PATCH 1/2] tools/sched_ext: Add SCX_OPS_CID_OPEN for cid-form schedulers
2026-07-18 10:10 [PATCHSET sched_ext/for-7.3] sched_ext: Rename the cid-form cgroup ops to cpuctl_* Tejun Heo
@ 2026-07-18 10:10 ` Tejun Heo
2026-07-18 10:10 ` [PATCH 2/2] sched_ext: Rename the cid-form cgroup ops to cpuctl_* Tejun Heo
1 sibling, 0 replies; 3+ messages in thread
From: Tejun Heo @ 2026-07-18 10:10 UTC (permalink / raw)
To: David Vernet, Andrea Righi, Changwoo Min
Cc: sched-ext, Emil Tsalapatis, linux-kernel, Tejun Heo
SCX_OPS_OPEN() clears compat-gated ops fields which the running kernel
lacks. The clears dereference cpu-form member names and compile for
cid-form skeletons only because both ops structs currently name their
cgroup ops identically, which an upcoming rename will end. No load-time
fix-up can apply to a cid-form scheduler anyway as the cid form postdates
every compat-gated op.
Factor the skeleton open path out of SCX_OPS_OPEN() and add
SCX_OPS_CID_OPEN() which uses only that shared part. Switch scx_qmap, the
only cid-form scheduler, over.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
tools/sched_ext/include/scx/compat.h | 30 ++++++++++++++++++++--------
tools/sched_ext/scx_qmap.c | 2 +-
2 files changed, 23 insertions(+), 9 deletions(-)
diff --git a/tools/sched_ext/include/scx/compat.h b/tools/sched_ext/include/scx/compat.h
index 23d9ef3e4c9d..7757252d52e2 100644
--- a/tools/sched_ext/include/scx/compat.h
+++ b/tools/sched_ext/include/scx/compat.h
@@ -154,7 +154,7 @@ static inline long scx_hotplug_seq(void)
* struct sched_ext_ops can change over time. Two complementary mechanisms
* keep BPF schedulers built against newer headers running on older kernels:
*
- * 1. Load-time fix-up (this macro). For each optional ops callback or field
+ * 1. Load-time fix-up (SCX_OPS_OPEN()). For each optional ops callback or field
* added to struct sched_ext_ops, an explicit stanza below probes the
* running kernel's BTF via __COMPAT_struct_has_field() and, if the field
* is missing, clears it in the in-memory struct_ops (with a warning to
@@ -176,16 +176,23 @@ static inline long scx_hotplug_seq(void)
* - v6.19: ops.cgroup_set_idle()
* - v7.1: ops.sub_attach(), ops.sub_detach(), ops.sub_cgroup_id
*/
+#define __SCX_OPS_OPEN(__ops_name, __scx_name, __ops_struct) ({ \
+ struct __scx_name *__oskel; \
+ \
+ SCX_BUG_ON(!__COMPAT_struct_has_field(__ops_struct, "dump"), \
+ __ops_struct ".dump() missing, kernel too old?"); \
+ \
+ __oskel = __scx_name##__open(); \
+ SCX_BUG_ON(!__oskel, "Could not open " #__scx_name); \
+ __oskel->struct_ops.__ops_name->hotplug_seq = scx_hotplug_seq(); \
+ SCX_ENUM_INIT(__oskel); \
+ __oskel; \
+})
+
#define SCX_OPS_OPEN(__ops_name, __scx_name) ({ \
struct __scx_name *__skel; \
\
- SCX_BUG_ON(!__COMPAT_struct_has_field("sched_ext_ops", "dump"), \
- "sched_ext_ops.dump() missing, kernel too old?"); \
- \
- __skel = __scx_name##__open(); \
- SCX_BUG_ON(!__skel, "Could not open " #__scx_name); \
- __skel->struct_ops.__ops_name->hotplug_seq = scx_hotplug_seq(); \
- SCX_ENUM_INIT(__skel); \
+ __skel = __SCX_OPS_OPEN(__ops_name, __scx_name, "sched_ext_ops"); \
if (__skel->struct_ops.__ops_name->cgroup_set_bandwidth && \
!__COMPAT_struct_has_field("sched_ext_ops", "cgroup_set_bandwidth")) { \
fprintf(stderr, "WARNING: kernel doesn't support ops.cgroup_set_bandwidth()\n"); \
@@ -214,6 +221,13 @@ static inline long scx_hotplug_seq(void)
__skel; \
})
+/*
+ * Open a cid-form (struct sched_ext_ops_cid) skeleton. The cid form postdates
+ * every op the load-time fix-ups above handle, so none of them apply.
+ */
+#define SCX_OPS_CID_OPEN(__ops_name, __scx_name) \
+ __SCX_OPS_OPEN(__ops_name, __scx_name, "sched_ext_ops_cid")
+
/*
* Associate non-struct_ops BPF programs with the scheduler's struct_ops map so
* that scx_prog_sched() can determine which scheduler a BPF program belongs
diff --git a/tools/sched_ext/scx_qmap.c b/tools/sched_ext/scx_qmap.c
index 46892b4bb448..ddb524b4946c 100644
--- a/tools/sched_ext/scx_qmap.c
+++ b/tools/sched_ext/scx_qmap.c
@@ -251,7 +251,7 @@ int main(int argc, char **argv)
}
restart:
optind = 1;
- skel = SCX_OPS_OPEN(qmap_ops, scx_qmap);
+ skel = SCX_OPS_CID_OPEN(qmap_ops, scx_qmap);
skel->rodata->slice_ns = __COMPAT_ENUM_OR_ZERO("scx_public_consts", "SCX_SLICE_DFL");
skel->rodata->max_tasks = 16384;
--
2.55.0
^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH 2/2] sched_ext: Rename the cid-form cgroup ops to cpuctl_*
2026-07-18 10:10 [PATCHSET sched_ext/for-7.3] sched_ext: Rename the cid-form cgroup ops to cpuctl_* Tejun Heo
2026-07-18 10:10 ` [PATCH 1/2] tools/sched_ext: Add SCX_OPS_CID_OPEN for cid-form schedulers Tejun Heo
@ 2026-07-18 10:10 ` Tejun Heo
1 sibling, 0 replies; 3+ messages in thread
From: Tejun Heo @ 2026-07-18 10:10 UTC (permalink / raw)
To: David Vernet, Andrea Righi, Changwoo Min
Cc: sched-ext, Emil Tsalapatis, linux-kernel, Tejun Heo
Two unrelated things go by "cgroup" in the cid form. Sub-schedulers attach
to cgroups, and the cgroup_*() ops deliver cpu controller events. While the
ops names suggest cgroup2 hierarchy, they actually operate on the cpu
controller.
Rename them to cpuctl_* in struct sched_ext_ops_cid, which has no users
outside scx_qmap yet. The cpu form is deployed ABI and keeps the old names.
The layout is unchanged and the kernel keeps calling through the cpu-form
union view.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
kernel/sched/ext/ext.c | 36 +++++++++++++++++-----------------
kernel/sched/ext/internal.h | 25 ++++++++++++-----------
tools/sched_ext/scx_qmap.bpf.c | 22 ++++++++++-----------
tools/sched_ext/scx_qmap.c | 2 +-
tools/sched_ext/scx_qmap.h | 2 +-
5 files changed, 43 insertions(+), 44 deletions(-)
diff --git a/kernel/sched/ext/ext.c b/kernel/sched/ext/ext.c
index 58cd971e5fc5..b730eac4b13f 100644
--- a/kernel/sched/ext/ext.c
+++ b/kernel/sched/ext/ext.c
@@ -7952,14 +7952,14 @@ static struct sched_ext_ops_cid __bpf_ops_sched_ext_ops_cid = {
.enable = sched_ext_ops__enable,
.disable = sched_ext_ops__disable,
#ifdef CONFIG_EXT_GROUP_SCHED
- .cgroup_init = sched_ext_ops__cgroup_init,
- .cgroup_exit = sched_ext_ops__cgroup_exit,
- .cgroup_prep_move = sched_ext_ops__cgroup_prep_move,
- .cgroup_move = sched_ext_ops__cgroup_move,
- .cgroup_cancel_move = sched_ext_ops__cgroup_cancel_move,
- .cgroup_set_weight = sched_ext_ops__cgroup_set_weight,
- .cgroup_set_bandwidth = sched_ext_ops__cgroup_set_bandwidth,
- .cgroup_set_idle = sched_ext_ops__cgroup_set_idle,
+ .cpuctl_init = sched_ext_ops__cgroup_init,
+ .cpuctl_exit = sched_ext_ops__cgroup_exit,
+ .cpuctl_prep_move = sched_ext_ops__cgroup_prep_move,
+ .cpuctl_move = sched_ext_ops__cgroup_move,
+ .cpuctl_cancel_move = sched_ext_ops__cgroup_cancel_move,
+ .cpuctl_set_weight = sched_ext_ops__cgroup_set_weight,
+ .cpuctl_set_bandwidth = sched_ext_ops__cgroup_set_bandwidth,
+ .cpuctl_set_idle = sched_ext_ops__cgroup_set_idle,
#endif
.sub_attach = sched_ext_ops__sub_attach,
.sub_detach = sched_ext_ops__sub_detach,
@@ -10479,22 +10479,22 @@ static int __init scx_init(void)
CID_OFFSET_MATCH(init_cids, init_cids);
CID_OFFSET_MATCH(init, init);
CID_OFFSET_MATCH(exit, exit);
-#ifdef CONFIG_EXT_GROUP_SCHED
- CID_OFFSET_MATCH(cgroup_init, cgroup_init);
- CID_OFFSET_MATCH(cgroup_exit, cgroup_exit);
- CID_OFFSET_MATCH(cgroup_prep_move, cgroup_prep_move);
- CID_OFFSET_MATCH(cgroup_move, cgroup_move);
- CID_OFFSET_MATCH(cgroup_cancel_move, cgroup_cancel_move);
- CID_OFFSET_MATCH(cgroup_set_weight, cgroup_set_weight);
- CID_OFFSET_MATCH(cgroup_set_bandwidth, cgroup_set_bandwidth);
- CID_OFFSET_MATCH(cgroup_set_idle, cgroup_set_idle);
-#endif
/* renamed callbacks must occupy the same slot as their cpu-form sibling */
CID_OFFSET_MATCH(select_cpu, select_cid);
CID_OFFSET_MATCH(set_cpumask, set_cmask);
CID_OFFSET_MATCH(cpu_online, cid_online);
CID_OFFSET_MATCH(cpu_offline, cid_offline);
CID_OFFSET_MATCH(dump_cpu, dump_cid);
+#ifdef CONFIG_EXT_GROUP_SCHED
+ CID_OFFSET_MATCH(cgroup_init, cpuctl_init);
+ CID_OFFSET_MATCH(cgroup_exit, cpuctl_exit);
+ CID_OFFSET_MATCH(cgroup_prep_move, cpuctl_prep_move);
+ CID_OFFSET_MATCH(cgroup_move, cpuctl_move);
+ CID_OFFSET_MATCH(cgroup_cancel_move, cpuctl_cancel_move);
+ CID_OFFSET_MATCH(cgroup_set_weight, cpuctl_set_weight);
+ CID_OFFSET_MATCH(cgroup_set_bandwidth, cpuctl_set_bandwidth);
+ CID_OFFSET_MATCH(cgroup_set_idle, cpuctl_set_idle);
+#endif
/* @priv tail must align since both share the same data block */
CID_OFFSET_MATCH(priv, priv);
/*
diff --git a/kernel/sched/ext/internal.h b/kernel/sched/ext/internal.h
index 0c0a8fdaa2c4..26bfda216524 100644
--- a/kernel/sched/ext/internal.h
+++ b/kernel/sched/ext/internal.h
@@ -992,6 +992,7 @@ struct sched_ext_ops {
* - cpu_online -> cid_online
* - cpu_offline -> cid_offline
* - dump_cpu -> dump_cid
+ * - cgroup_* -> cpuctl_* (they track the cgroup cpu controller)
* - cpu_acquire/cpu_release -> not present (deprecated in sched_ext_ops)
*
* BPF schedulers using this type cannot call cpu-form scx_bpf_* kfuncs;
@@ -1027,19 +1028,17 @@ struct sched_ext_ops_cid {
void (*dump_cid)(struct scx_dump_ctx *ctx, s32 cid, bool idle);
void (*dump_task)(struct scx_dump_ctx *ctx, struct task_struct *p);
#ifdef CONFIG_EXT_GROUP_SCHED
- s32 (*cgroup_init)(struct cgroup *cgrp,
- struct scx_cgroup_init_args *args);
- void (*cgroup_exit)(struct cgroup *cgrp);
- s32 (*cgroup_prep_move)(struct task_struct *p,
- struct cgroup *from, struct cgroup *to);
- void (*cgroup_move)(struct task_struct *p,
- struct cgroup *from, struct cgroup *to);
- void (*cgroup_cancel_move)(struct task_struct *p,
- struct cgroup *from, struct cgroup *to);
- void (*cgroup_set_weight)(struct cgroup *cgrp, u32 weight);
- void (*cgroup_set_bandwidth)(struct cgroup *cgrp,
- u64 period_us, u64 quota_us, u64 burst_us);
- void (*cgroup_set_idle)(struct cgroup *cgrp, bool idle);
+ s32 (*cpuctl_init)(struct cgroup *cgrp, struct scx_cgroup_init_args *args);
+ void (*cpuctl_exit)(struct cgroup *cgrp);
+ s32 (*cpuctl_prep_move)(struct task_struct *p, struct cgroup *from,
+ struct cgroup *to);
+ void (*cpuctl_move)(struct task_struct *p, struct cgroup *from, struct cgroup *to);
+ void (*cpuctl_cancel_move)(struct task_struct *p, struct cgroup *from,
+ struct cgroup *to);
+ void (*cpuctl_set_weight)(struct cgroup *cgrp, u32 weight);
+ void (*cpuctl_set_bandwidth)(struct cgroup *cgrp, u64 period_us, u64 quota_us,
+ u64 burst_us);
+ void (*cpuctl_set_idle)(struct cgroup *cgrp, bool idle);
#endif /* CONFIG_EXT_GROUP_SCHED */
s32 (*sub_attach)(struct scx_sub_attach_args *args);
void (*sub_detach)(struct scx_sub_detach_args *args);
diff --git a/tools/sched_ext/scx_qmap.bpf.c b/tools/sched_ext/scx_qmap.bpf.c
index 925ae1a1d440..aead17658573 100644
--- a/tools/sched_ext/scx_qmap.bpf.c
+++ b/tools/sched_ext/scx_qmap.bpf.c
@@ -1014,7 +1014,7 @@ void BPF_STRUCT_OPS(qmap_dump_task, struct scx_dump_ctx *dctx, struct task_struc
taskc->force_local, taskc->core_sched_seq);
}
-s32 BPF_STRUCT_OPS(qmap_cgroup_init, struct cgroup *cgrp, struct scx_cgroup_init_args *args)
+s32 BPF_STRUCT_OPS(qmap_cpuctl_init, struct cgroup *cgrp, struct scx_cgroup_init_args *args)
{
QMAP_TOUCH_ARENA();
@@ -1036,7 +1036,7 @@ s32 BPF_STRUCT_OPS(qmap_cgroup_init, struct cgroup *cgrp, struct scx_cgroup_init
static void redistribute(void);
-void BPF_STRUCT_OPS(qmap_cgroup_set_weight, struct cgroup *cgrp, u32 weight)
+void BPF_STRUCT_OPS(qmap_cpuctl_set_weight, struct cgroup *cgrp, u32 weight)
{
u64 cgid = cgrp->kn->id;
s32 i;
@@ -1062,16 +1062,16 @@ void BPF_STRUCT_OPS(qmap_cgroup_set_weight, struct cgroup *cgrp, u32 weight)
}
}
-void BPF_STRUCT_OPS(qmap_cgroup_set_bandwidth, struct cgroup *cgrp,
- u64 period_us, u64 quota_us, u64 burst_us)
+void BPF_STRUCT_OPS(qmap_cpuctl_set_bandwidth, struct cgroup *cgrp, u64 period_us,
+ u64 quota_us, u64 burst_us)
{
if (print_msgs)
bpf_printk("CGRP SET %llu period=%lu quota=%ld burst=%lu",
cgrp->kn->id, period_us, quota_us, burst_us);
}
-void BPF_STRUCT_OPS(qmap_cgroup_move, struct task_struct *p,
- struct cgroup *from, struct cgroup *to)
+void BPF_STRUCT_OPS(qmap_cpuctl_move, struct task_struct *p, struct cgroup *from,
+ struct cgroup *to)
{
if (print_msgs)
bpf_printk("CGRP MOVE %d %llu -> %llu",
@@ -1890,7 +1890,7 @@ void BPF_STRUCT_OPS(qmap_exit, struct scx_exit_info *ei)
/*
* Seed a new sub slot with the cgroup's current weight. The kernel delivers
- * ops.cgroup_set_weight() only on value-changing writes, so a weight set
+ * ops.cpuctl_set_weight() only on value-changing writes, so a weight set
* before the sub attached would otherwise go unnoticed.
*/
static u32 cgrp_cur_weight(u64 cgid)
@@ -1989,10 +1989,10 @@ SCX_OPS_CID_DEFINE(qmap_ops,
.dump = (void *)qmap_dump,
.dump_cid = (void *)qmap_dump_cid,
.dump_task = (void *)qmap_dump_task,
- .cgroup_init = (void *)qmap_cgroup_init,
- .cgroup_set_weight = (void *)qmap_cgroup_set_weight,
- .cgroup_set_bandwidth = (void *)qmap_cgroup_set_bandwidth,
- .cgroup_move = (void *)qmap_cgroup_move,
+ .cpuctl_init = (void *)qmap_cpuctl_init,
+ .cpuctl_set_weight = (void *)qmap_cpuctl_set_weight,
+ .cpuctl_set_bandwidth = (void *)qmap_cpuctl_set_bandwidth,
+ .cpuctl_move = (void *)qmap_cpuctl_move,
.sub_attach = (void *)qmap_sub_attach,
.sub_detach = (void *)qmap_sub_detach,
.sub_caps_updated = (void *)qmap_sub_caps_updated,
diff --git a/tools/sched_ext/scx_qmap.c b/tools/sched_ext/scx_qmap.c
index ddb524b4946c..27ffda1c519e 100644
--- a/tools/sched_ext/scx_qmap.c
+++ b/tools/sched_ext/scx_qmap.c
@@ -70,7 +70,7 @@ const char help_fmt[] =
" -i SEC Stats interval, seconds (default 5)\n"
" -R MS Round-robin period for time-shared cpus, ms (default 200)\n"
" -J MODE Fault injection (wrong-cid: dispatch to a cid not held,\n"
-" init-fail/cgrp-init-fail: fail init_task/cgroup_init for\n"
+" init-fail/cgrp-init-fail: fail init_task/cpuctl_init for\n"
" \"qmfail*\" comms/cgroups)\n"
" -v Print libbpf debug messages\n"
" -h Display this help and exit\n";
diff --git a/tools/sched_ext/scx_qmap.h b/tools/sched_ext/scx_qmap.h
index cc2840e7aa3c..c42f7ef74b89 100644
--- a/tools/sched_ext/scx_qmap.h
+++ b/tools/sched_ext/scx_qmap.h
@@ -65,7 +65,7 @@ enum qmap_inject {
QMAP_INJ_OFF = 0,
QMAP_INJ_WRONG_CID = 1, /* dispatch to a cid we don't hold */
QMAP_INJ_INIT_FAIL = 2, /* fail init_task for "qmfail*" comms */
- QMAP_INJ_CGRP_INIT_FAIL = 3, /* fail cgroup_init for "qmfail*" cgroups */
+ QMAP_INJ_CGRP_INIT_FAIL = 3, /* fail cpuctl_init for "qmfail*" cgroups */
};
/*
--
2.55.0
^ permalink raw reply related [flat|nested] 3+ messages in thread