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1/* SPDX-License-Identifier: GPL-2.0 */2/*3 * Copyright (c) 2024 Meta Platforms, Inc. and affiliates.4 * Copyright (c) 2024 David Vernet <dvernet@meta.com>5 */6#include <scx/common.bpf.h>7 8char _license[] SEC("license") = "GPL";9const volatile s32 nr_cpus;10 11UEI_DEFINE(uei);12 13struct {14 __uint(type, BPF_MAP_TYPE_QUEUE);15 __uint(max_entries, 8192);16 __type(value, s32);17} queue SEC(".maps");18 19s32 BPF_STRUCT_OPS(dsp_local_on_select_cpu, struct task_struct *p,20 s32 prev_cpu, u64 wake_flags)21{22 return prev_cpu;23}24 25void BPF_STRUCT_OPS(dsp_local_on_enqueue, struct task_struct *p,26 u64 enq_flags)27{28 s32 pid = p->pid;29 30 if (bpf_map_push_elem(&queue, &pid, 0))31 scx_bpf_error("Failed to enqueue %s[%d]", p->comm, p->pid);32}33 34void BPF_STRUCT_OPS(dsp_local_on_dispatch, s32 cpu, struct task_struct *prev)35{36 s32 pid, target;37 struct task_struct *p;38 39 if (bpf_map_pop_elem(&queue, &pid))40 return;41 42 p = bpf_task_from_pid(pid);43 if (!p)44 return;45 46 target = bpf_get_prandom_u32() % nr_cpus;47 48 scx_bpf_dispatch(p, SCX_DSQ_LOCAL_ON | target, SCX_SLICE_DFL, 0);49 bpf_task_release(p);50}51 52void BPF_STRUCT_OPS(dsp_local_on_exit, struct scx_exit_info *ei)53{54 UEI_RECORD(uei, ei);55}56 57SEC(".struct_ops.link")58struct sched_ext_ops dsp_local_on_ops = {59 .select_cpu = (void *) dsp_local_on_select_cpu,60 .enqueue = (void *) dsp_local_on_enqueue,61 .dispatch = (void *) dsp_local_on_dispatch,62 .exit = (void *) dsp_local_on_exit,63 .name = "dsp_local_on",64 .timeout_ms = 1000U,65};66