From 6203ef73fa5c0358f7960b038628259be1448724 Mon Sep 17 00:00:00 2001 From: Hongyan Xia Date: Mon, 8 Jul 2024 15:01:18 +0100 Subject: [PATCH] sched/ext: Add BPF function to fetch rq rq contains many useful fields to implement a custom scheduler. For example, various clock signals like clock_task and clock_pelt can be used to track load. It also contains stats in other sched_classes, which are useful to drive scheduling decisions in ext. tj: Put the new helper below scx_bpf_task_*() helpers. Signed-off-by: Hongyan Xia Signed-off-by: Tejun Heo --- kernel/sched/ext.c | 13 +++++++++++++ tools/sched_ext/include/scx/common.bpf.h | 1 + 2 files changed, 14 insertions(+) diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 33bfb5a88b48..525102f3ff5b 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -6113,6 +6113,18 @@ __bpf_kfunc s32 scx_bpf_task_cpu(const struct task_struct *p) return task_cpu(p); } +/** + * scx_bpf_cpu_rq - Fetch the rq of a CPU + * @cpu: CPU of the rq + */ +__bpf_kfunc struct rq *scx_bpf_cpu_rq(s32 cpu) +{ + if (!ops_cpu_valid(cpu, NULL)) + return NULL; + + return cpu_rq(cpu); +} + __bpf_kfunc_end_defs(); BTF_KFUNCS_START(scx_kfunc_ids_any) @@ -6137,6 +6149,7 @@ BTF_ID_FLAGS(func, scx_bpf_pick_idle_cpu, KF_RCU) BTF_ID_FLAGS(func, scx_bpf_pick_any_cpu, KF_RCU) BTF_ID_FLAGS(func, scx_bpf_task_running, KF_RCU) BTF_ID_FLAGS(func, scx_bpf_task_cpu, KF_RCU) +BTF_ID_FLAGS(func, scx_bpf_cpu_rq) BTF_KFUNCS_END(scx_kfunc_ids_any) static const struct btf_kfunc_id_set scx_kfunc_set_any = { diff --git a/tools/sched_ext/include/scx/common.bpf.h b/tools/sched_ext/include/scx/common.bpf.h index dbbda0e35c5d..965d20324114 100644 --- a/tools/sched_ext/include/scx/common.bpf.h +++ b/tools/sched_ext/include/scx/common.bpf.h @@ -57,6 +57,7 @@ s32 scx_bpf_pick_idle_cpu(const cpumask_t *cpus_allowed, u64 flags) __ksym; 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; +struct rq *scx_bpf_cpu_rq(s32 cpu) __ksym; static inline __attribute__((format(printf, 1, 2))) void ___scx_bpf_bstr_format_checker(const char *fmt, ...) {}