From: Tejun Heo <tj@kernel.org>
Date: Tue, 7 Oct 2025 19:06:57 +0000 (-1000)
Subject: sched_ext/tools: Add compat wrapper for scx_bpf_task_set_slice/dsq_vtime()
X-Git-Tag: v6.19-rc1~177^2~42
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bd7143e74e8ce0b35b32fa76e92d78e52cb12883;p=thirdparty%2Flinux.git

sched_ext/tools: Add compat wrapper for scx_bpf_task_set_slice/dsq_vtime()

for sub-scheduler authority checks. Add compat wrappers which fall back to
direct p->scx field writes on older kernels.

Suggested-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---

diff --git a/tools/sched_ext/include/scx/common.bpf.h b/tools/sched_ext/include/scx/common.bpf.h
index 522c90d0ced27..eb3c99445cb3e 100644
--- a/tools/sched_ext/include/scx/common.bpf.h
+++ b/tools/sched_ext/include/scx/common.bpf.h
@@ -101,8 +101,6 @@ s32 scx_bpf_pick_any_cpu_node(const cpumask_t *cpus_allowed, int node, u64 flags
 s32 scx_bpf_pick_any_cpu(const cpumask_t *cpus_allowed, u64 flags) __ksym;
 bool scx_bpf_task_running(const struct task_struct *p) __ksym;
 s32 scx_bpf_task_cpu(const struct task_struct *p) __ksym;
-bool scx_bpf_task_set_slice(struct task_struct *p, u64 slice) __ksym __weak;
-bool scx_bpf_task_set_dsq_vtime(struct task_struct *p, u64 vtime) __ksym __weak;
 struct rq *scx_bpf_cpu_rq(s32 cpu) __ksym;
 struct rq *scx_bpf_locked_rq(void) __ksym;
 struct task_struct *scx_bpf_cpu_curr(s32 cpu) __ksym __weak;
diff --git a/tools/sched_ext/include/scx/compat.bpf.h b/tools/sched_ext/include/scx/compat.bpf.h
index 33c26928f4e96..e487c10b5e07f 100644
--- a/tools/sched_ext/include/scx/compat.bpf.h
+++ b/tools/sched_ext/include/scx/compat.bpf.h
@@ -234,6 +234,30 @@ scx_bpf_dsq_insert(struct task_struct *p, u64 dsq_id, u64 slice, u64 enq_flags)
 	}
 }
 
+/*
+ * v6.19: scx_bpf_task_set_slice() and scx_bpf_task_set_dsq_vtime() added to for
+ * sub-sched authority checks. Drop the wrappers and move the decls to
+ * common.bpf.h after v6.22.
+ */
+bool scx_bpf_task_set_slice___new(struct task_struct *p, u64 slice) __ksym __weak;
+bool scx_bpf_task_set_dsq_vtime___new(struct task_struct *p, u64 vtime) __ksym __weak;
+
+static inline void scx_bpf_task_set_slice(struct task_struct *p, u64 slice)
+{
+	if (bpf_ksym_exists(scx_bpf_task_set_slice___new))
+		scx_bpf_task_set_slice___new(p, slice);
+	else
+		p->scx.slice = slice;
+}
+
+static inline void scx_bpf_task_set_dsq_vtime(struct task_struct *p, u64 vtime)
+{
+	if (bpf_ksym_exists(scx_bpf_task_set_dsq_vtime___new))
+		scx_bpf_task_set_dsq_vtime___new(p, vtime);
+	else
+		p->scx.dsq_vtime = vtime;
+}
+
 /*
  * Define sched_ext_ops. This may be expanded to define multiple variants for
  * backward compatibility. See compat.h::SCX_OPS_LOAD/ATTACH().