| Joel Fernandes | c5c0516 | 2018-10-16 13:26:56 -0700 | [diff] [blame] | 1 | /* |
| 2 | * time_in_state eBPF program |
| 3 | * |
| 4 | * Copyright (C) 2018 Google |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License version |
| 8 | * 2 as published by the Free Software Foundation. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | */ |
| 16 | |
| 17 | #include "helpers.h" |
| 18 | |
| 19 | struct time_key { |
| 20 | uint32_t uid; |
| 21 | uint32_t freq; |
| 22 | }; |
| 23 | |
| 24 | struct bpf_map_def SEC("maps") uid_times = { |
| 25 | .type = BPF_MAP_TYPE_PERCPU_HASH, |
| 26 | .key_size = sizeof(struct time_key), |
| 27 | .value_size = sizeof(uint64_t), |
| 28 | .max_entries = 10240, |
| 29 | }; |
| 30 | |
| 31 | struct bpf_map_def SEC("maps") cpu_last_update = { |
| 32 | .type = BPF_MAP_TYPE_PERCPU_ARRAY, |
| 33 | .key_size = sizeof(int), |
| 34 | .value_size = sizeof(uint64_t), |
| 35 | .max_entries = 1, |
| 36 | }; |
| 37 | |
| 38 | struct bpf_map_def SEC("maps") cpu_freq = { |
| 39 | .type = BPF_MAP_TYPE_ARRAY, |
| 40 | .key_size = sizeof(int), |
| 41 | .value_size = sizeof(uint32_t), |
| 42 | /* Assume max of 1024 CPUs */ |
| 43 | .max_entries = 1024, |
| 44 | }; |
| 45 | |
| 46 | struct switch_args { |
| 47 | unsigned long long ignore; |
| 48 | char prev_comm[16]; |
| 49 | int prev_pid; |
| 50 | int prev_prio; |
| 51 | long long prev_state; |
| 52 | char next_comm[16]; |
| 53 | int next_pid; |
| 54 | int next_prio; |
| 55 | }; |
| 56 | |
| 57 | SEC("tracepoint/sched/sched_switch") |
| 58 | int tp_sched_switch(struct switch_args* args) { |
| 59 | uint32_t zero = 0; |
| 60 | uint64_t* last = bpf_map_lookup_elem(&cpu_last_update, &zero); |
| 61 | if (!last) return 0; |
| 62 | uint64_t old_last = *last; |
| 63 | uint64_t time = bpf_ktime_get_ns(); |
| 64 | *last = time; |
| 65 | uint32_t cpu = bpf_get_smp_processor_id(); |
| 66 | uint32_t* freq = bpf_map_lookup_elem(&cpu_freq, &cpu); |
| 67 | if (args->prev_pid && old_last && freq && *freq) { |
| 68 | uint32_t uid = bpf_get_current_uid_gid(); |
| 69 | struct time_key key = {.uid = uid, .freq = *freq}; |
| 70 | uint64_t* tot_time = bpf_map_lookup_elem(&uid_times, &key); |
| 71 | uint64_t delta = time - old_last; |
| 72 | if (!tot_time) |
| 73 | bpf_map_update_elem(&uid_times, &key, &delta, BPF_ANY); |
| 74 | else |
| 75 | *tot_time += delta; |
| 76 | } |
| 77 | return 0; |
| 78 | } |
| 79 | |
| 80 | struct cpufreq_args { |
| 81 | unsigned long long ignore; |
| 82 | unsigned int state; |
| 83 | unsigned int cpu_id; |
| 84 | }; |
| 85 | |
| 86 | SEC("tracepoint/power/cpu_frequency") |
| 87 | int tp_cpufreq(struct cpufreq_args* args) { |
| 88 | unsigned int cpu = args->cpu_id; |
| 89 | unsigned int new = args->state; |
| 90 | bpf_map_update_elem(&cpu_freq, &cpu, &new, BPF_ANY); |
| 91 | return 0; |
| 92 | } |
| 93 | |
| 94 | char _license[] SEC("license") = "GPL"; |
