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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2023 Meta Platforms, Inc. and affiliates.
* Copyright (c) 2023 David Vernet <dvernet@meta.com>
* Copyright (c) 2023 Tejun Heo <tj@kernel.org>
*/
#include <scx/common.bpf.h>
char _license[] SEC("license") = "GPL";
UEI_DEFINE(uei);
s32 BPF_STRUCT_OPS(enq_select_cpu_select_cpu, struct task_struct *p,
s32 prev_cpu, u64 wake_flags)
{
/* Bounce all tasks to ops.enqueue() */
return prev_cpu;
}
void BPF_STRUCT_OPS(enq_select_cpu_enqueue, struct task_struct *p,
u64 enq_flags)
{
s32 cpu, prev_cpu = scx_bpf_task_cpu(p);
bool found = false;
cpu = scx_bpf_select_cpu_dfl(p, prev_cpu, 0, &found);
if (found) {
scx_bpf_dsq_insert(p, SCX_DSQ_LOCAL_ON | cpu, SCX_SLICE_DFL, enq_flags);
return;
}
scx_bpf_dsq_insert(p, SCX_DSQ_GLOBAL, SCX_SLICE_DFL, enq_flags);
}
void BPF_STRUCT_OPS(enq_select_cpu_exit, struct scx_exit_info *ei)
{
UEI_RECORD(uei, ei);
}
struct task_cpu_arg {
pid_t pid;
};
SEC("syscall")
int select_cpu_from_user(struct task_cpu_arg *input)
{
struct task_struct *p;
bool found = false;
s32 cpu;
p = bpf_task_from_pid(input->pid);
if (!p)
return -EINVAL;
bpf_rcu_read_lock();
cpu = scx_bpf_select_cpu_dfl(p, bpf_get_smp_processor_id(), 0, &found);
if (!found)
cpu = -EBUSY;
bpf_rcu_read_unlock();
bpf_task_release(p);
return cpu;
}
SEC(".struct_ops.link")
struct sched_ext_ops enq_select_cpu_ops = {
.select_cpu = (void *)enq_select_cpu_select_cpu,
.enqueue = (void *)enq_select_cpu_enqueue,
.exit = (void *)enq_select_cpu_exit,
.name = "enq_select_cpu",
.timeout_ms = 1000U,
};
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