From 0e9b4c10e833dbcfcdba63497463f1272c5efe4d Mon Sep 17 00:00:00 2001 From: Andrea Righi Date: Mon, 24 Feb 2025 17:49:21 +0100 Subject: [PATCH] sched_ext: idle: Introduce scx_bpf_nr_node_ids() Similarly to scx_bpf_nr_cpu_ids(), introduce a new kfunc scx_bpf_nr_node_ids() to expose the maximum number of NUMA nodes in the system. BPF schedulers can use this information together with the new node-aware kfuncs, for example to create per-node DSQs, validate node IDs, etc. Signed-off-by: Andrea Righi Signed-off-by: Tejun Heo --- kernel/sched/ext.c | 11 +++++++++++ tools/sched_ext/include/scx/common.bpf.h | 1 + tools/sched_ext/include/scx/compat.bpf.h | 4 ++++ 3 files changed, 16 insertions(+) diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 95603db36f04..74b247c36b3d 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -7113,6 +7113,16 @@ __bpf_kfunc void scx_bpf_cpuperf_set(s32 cpu, u32 perf) } } +/** + * scx_bpf_nr_node_ids - Return the number of possible node IDs + * + * All valid node IDs in the system are smaller than the returned value. + */ +__bpf_kfunc u32 scx_bpf_nr_node_ids(void) +{ + return nr_node_ids; +} + /** * scx_bpf_nr_cpu_ids - Return the number of possible CPU IDs * @@ -7325,6 +7335,7 @@ BTF_ID_FLAGS(func, scx_bpf_dump_bstr, KF_TRUSTED_ARGS) BTF_ID_FLAGS(func, scx_bpf_cpuperf_cap) BTF_ID_FLAGS(func, scx_bpf_cpuperf_cur) BTF_ID_FLAGS(func, scx_bpf_cpuperf_set) +BTF_ID_FLAGS(func, scx_bpf_nr_node_ids) BTF_ID_FLAGS(func, scx_bpf_nr_cpu_ids) BTF_ID_FLAGS(func, scx_bpf_get_possible_cpumask, KF_ACQUIRE) BTF_ID_FLAGS(func, scx_bpf_get_online_cpumask, KF_ACQUIRE) diff --git a/tools/sched_ext/include/scx/common.bpf.h b/tools/sched_ext/include/scx/common.bpf.h index ca7cc4108b45..0e5587759090 100644 --- a/tools/sched_ext/include/scx/common.bpf.h +++ b/tools/sched_ext/include/scx/common.bpf.h @@ -70,6 +70,7 @@ void scx_bpf_dump_bstr(char *fmt, unsigned long long *data, u32 data_len) __ksym u32 scx_bpf_cpuperf_cap(s32 cpu) __ksym __weak; u32 scx_bpf_cpuperf_cur(s32 cpu) __ksym __weak; void scx_bpf_cpuperf_set(s32 cpu, u32 perf) __ksym __weak; +u32 scx_bpf_nr_node_ids(void) __ksym __weak; u32 scx_bpf_nr_cpu_ids(void) __ksym __weak; int scx_bpf_cpu_node(s32 cpu) __ksym __weak; const struct cpumask *scx_bpf_get_possible_cpumask(void) __ksym __weak; diff --git a/tools/sched_ext/include/scx/compat.bpf.h b/tools/sched_ext/include/scx/compat.bpf.h index 5a9bcdb52e79..266f94fe479b 100644 --- a/tools/sched_ext/include/scx/compat.bpf.h +++ b/tools/sched_ext/include/scx/compat.bpf.h @@ -189,6 +189,10 @@ static inline bool __COMPAT_is_enq_cpu_selected(u64 enq_flags) * * Preserve the following __COMPAT_scx_*_node macros until v6.17. */ +#define __COMPAT_scx_bpf_nr_node_ids() \ + (bpf_ksym_exists(scx_bpf_nr_node_ids) ? \ + scx_bpf_nr_node_ids() : 1U) + #define __COMPAT_scx_bpf_cpu_node(cpu) \ (bpf_ksym_exists(scx_bpf_cpu_node) ? \ scx_bpf_cpu_node(cpu) : 0) -- 2.50.1