/* maintain timestamp at the beginning of contention */
struct {
- __uint(type, BPF_MAP_TYPE_TASK_STORAGE);
- __uint(map_flags, BPF_F_NO_PREALLOC);
+ __uint(type, BPF_MAP_TYPE_HASH);
__type(key, int);
__type(value, struct tstamp_data);
+ __uint(max_entries, MAX_ENTRIES);
} tstamp SEC(".maps");
/* actual lock contention statistics */
SEC("tp_btf/contention_begin")
int contention_begin(u64 *ctx)
{
- struct task_struct *curr;
+ __u32 pid;
struct tstamp_data *pelem;
if (!enabled || !can_record())
return 0;
- curr = bpf_get_current_task_btf();
- pelem = bpf_task_storage_get(&tstamp, curr, NULL,
- BPF_LOCAL_STORAGE_GET_F_CREATE);
- if (!pelem || pelem->lock)
+ pid = bpf_get_current_pid_tgid();
+ pelem = bpf_map_lookup_elem(&tstamp, &pid);
+ if (pelem && pelem->lock)
return 0;
+ if (pelem == NULL) {
+ struct tstamp_data zero = {};
+
+ bpf_map_update_elem(&tstamp, &pid, &zero, BPF_ANY);
+ pelem = bpf_map_lookup_elem(&tstamp, &pid);
+ if (pelem == NULL) {
+ lost++;
+ return 0;
+ }
+ }
+
pelem->timestamp = bpf_ktime_get_ns();
pelem->lock = (__u64)ctx[0];
pelem->flags = (__u32)ctx[1];
SEC("tp_btf/contention_end")
int contention_end(u64 *ctx)
{
- struct task_struct *curr;
+ __u32 pid;
struct tstamp_data *pelem;
struct contention_key key;
struct contention_data *data;
if (!enabled)
return 0;
- curr = bpf_get_current_task_btf();
- pelem = bpf_task_storage_get(&tstamp, curr, NULL, 0);
+ pid = bpf_get_current_pid_tgid();
+ pelem = bpf_map_lookup_elem(&tstamp, &pid);
if (!pelem || pelem->lock != ctx[0])
return 0;
};
bpf_map_update_elem(&lock_stat, &key, &first, BPF_NOEXIST);
- pelem->lock = 0;
+ bpf_map_delete_elem(&tstamp, &pid);
return 0;
}
if (data->min_time > duration)
data->min_time = duration;
- pelem->lock = 0;
+ bpf_map_delete_elem(&tstamp, &pid);
return 0;
}