| // SPDX-License-Identifier: GPL-2.0 |
| // Copyright (c) 2019 Facebook |
| #include <linux/bpf.h> |
| #include <linux/version.h> |
| #include <bpf/bpf_helpers.h> |
| |
| struct hmap_elem { |
| volatile int cnt; |
| struct bpf_spin_lock lock; |
| int test_padding; |
| }; |
| |
| struct { |
| __uint(type, BPF_MAP_TYPE_HASH); |
| __uint(max_entries, 1); |
| __type(key, int); |
| __type(value, struct hmap_elem); |
| } hmap SEC(".maps"); |
| |
| struct cls_elem { |
| struct bpf_spin_lock lock; |
| volatile int cnt; |
| }; |
| |
| struct { |
| __uint(type, BPF_MAP_TYPE_CGROUP_STORAGE); |
| __type(key, struct bpf_cgroup_storage_key); |
| __type(value, struct cls_elem); |
| } cls_map SEC(".maps"); |
| |
| struct bpf_vqueue { |
| struct bpf_spin_lock lock; |
| /* 4 byte hole */ |
| unsigned long long lasttime; |
| int credit; |
| unsigned int rate; |
| }; |
| |
| struct { |
| __uint(type, BPF_MAP_TYPE_ARRAY); |
| __uint(max_entries, 1); |
| __type(key, int); |
| __type(value, struct bpf_vqueue); |
| } vqueue SEC(".maps"); |
| |
| #define CREDIT_PER_NS(delta, rate) (((delta) * rate) >> 20) |
| |
| SEC("cgroup_skb/ingress") |
| int bpf_spin_lock_test(struct __sk_buff *skb) |
| { |
| volatile int credit = 0, max_credit = 100, pkt_len = 64; |
| struct hmap_elem zero = {}, *val; |
| unsigned long long curtime; |
| struct bpf_vqueue *q; |
| struct cls_elem *cls; |
| int key = 0; |
| int err = 0; |
| |
| val = bpf_map_lookup_elem(&hmap, &key); |
| if (!val) { |
| bpf_map_update_elem(&hmap, &key, &zero, 0); |
| val = bpf_map_lookup_elem(&hmap, &key); |
| if (!val) { |
| err = 1; |
| goto err; |
| } |
| } |
| /* spin_lock in hash map run time test */ |
| bpf_spin_lock(&val->lock); |
| if (val->cnt) |
| val->cnt--; |
| else |
| val->cnt++; |
| if (val->cnt != 0 && val->cnt != 1) |
| err = 1; |
| bpf_spin_unlock(&val->lock); |
| |
| /* spin_lock in array. virtual queue demo */ |
| q = bpf_map_lookup_elem(&vqueue, &key); |
| if (!q) |
| goto err; |
| curtime = bpf_ktime_get_ns(); |
| bpf_spin_lock(&q->lock); |
| q->credit += CREDIT_PER_NS(curtime - q->lasttime, q->rate); |
| q->lasttime = curtime; |
| if (q->credit > max_credit) |
| q->credit = max_credit; |
| q->credit -= pkt_len; |
| credit = q->credit; |
| bpf_spin_unlock(&q->lock); |
| |
| /* spin_lock in cgroup local storage */ |
| cls = bpf_get_local_storage(&cls_map, 0); |
| bpf_spin_lock(&cls->lock); |
| cls->cnt++; |
| bpf_spin_unlock(&cls->lock); |
| |
| err: |
| return err; |
| } |
| char _license[] SEC("license") = "GPL"; |