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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 | // SPDX-License-Identifier: GPL-2.0 #include <linux/version.h> #include <linux/ptrace.h> #include <uapi/linux/bpf.h> #include <bpf/bpf_helpers.h> /* * The CPU number, cstate number and pstate number are based * on 96boards Hikey with octa CA53 CPUs. * * Every CPU have three idle states for cstate: * WFI, CPU_OFF, CLUSTER_OFF * * Every CPU have 5 operating points: * 208MHz, 432MHz, 729MHz, 960MHz, 1200MHz * * This code is based on these assumption and other platforms * need to adjust these definitions. */ #define MAX_CPU 8 #define MAX_PSTATE_ENTRIES 5 #define MAX_CSTATE_ENTRIES 3 static int cpu_opps[] = { 208000, 432000, 729000, 960000, 1200000 }; /* * my_map structure is used to record cstate and pstate index and * timestamp (Idx, Ts), when new event incoming we need to update * combination for new state index and timestamp (Idx`, Ts`). * * Based on (Idx, Ts) and (Idx`, Ts`) we can calculate the time * interval for the previous state: Duration(Idx) = Ts` - Ts. * * Every CPU has one below array for recording state index and * timestamp, and record for cstate and pstate saperately: * * +--------------------------+ * | cstate timestamp | * +--------------------------+ * | cstate index | * +--------------------------+ * | pstate timestamp | * +--------------------------+ * | pstate index | * +--------------------------+ */ #define MAP_OFF_CSTATE_TIME 0 #define MAP_OFF_CSTATE_IDX 1 #define MAP_OFF_PSTATE_TIME 2 #define MAP_OFF_PSTATE_IDX 3 #define MAP_OFF_NUM 4 struct { __uint(type, BPF_MAP_TYPE_ARRAY); __type(key, u32); __type(value, u64); __uint(max_entries, MAX_CPU * MAP_OFF_NUM); } my_map SEC(".maps"); /* cstate_duration records duration time for every idle state per CPU */ struct { __uint(type, BPF_MAP_TYPE_ARRAY); __type(key, u32); __type(value, u64); __uint(max_entries, MAX_CPU * MAX_CSTATE_ENTRIES); } cstate_duration SEC(".maps"); /* pstate_duration records duration time for every operating point per CPU */ struct { __uint(type, BPF_MAP_TYPE_ARRAY); __type(key, u32); __type(value, u64); __uint(max_entries, MAX_CPU * MAX_PSTATE_ENTRIES); } pstate_duration SEC(".maps"); /* * The trace events for cpu_idle and cpu_frequency are taken from: * /sys/kernel/tracing/events/power/cpu_idle/format * /sys/kernel/tracing/events/power/cpu_frequency/format * * These two events have same format, so define one common structure. */ struct cpu_args { u64 pad; u32 state; u32 cpu_id; }; /* calculate pstate index, returns MAX_PSTATE_ENTRIES for failure */ static u32 find_cpu_pstate_idx(u32 frequency) { u32 i; for (i = 0; i < sizeof(cpu_opps) / sizeof(u32); i++) { if (frequency == cpu_opps[i]) return i; } return i; } SEC("tracepoint/power/cpu_idle") int bpf_prog1(struct cpu_args *ctx) { u64 *cts, *pts, *cstate, *pstate, prev_state, cur_ts, delta; u32 key, cpu, pstate_idx; u64 *val; if (ctx->cpu_id > MAX_CPU) return 0; cpu = ctx->cpu_id; key = cpu * MAP_OFF_NUM + MAP_OFF_CSTATE_TIME; cts = bpf_map_lookup_elem(&my_map, &key); if (!cts) return 0; key = cpu * MAP_OFF_NUM + MAP_OFF_CSTATE_IDX; cstate = bpf_map_lookup_elem(&my_map, &key); if (!cstate) return 0; key = cpu * MAP_OFF_NUM + MAP_OFF_PSTATE_TIME; pts = bpf_map_lookup_elem(&my_map, &key); if (!pts) return 0; key = cpu * MAP_OFF_NUM + MAP_OFF_PSTATE_IDX; pstate = bpf_map_lookup_elem(&my_map, &key); if (!pstate) return 0; prev_state = *cstate; *cstate = ctx->state; if (!*cts) { *cts = bpf_ktime_get_ns(); return 0; } cur_ts = bpf_ktime_get_ns(); delta = cur_ts - *cts; *cts = cur_ts; /* * When state doesn't equal to (u32)-1, the cpu will enter * one idle state; for this case we need to record interval * for the pstate. * * OPP2 * +---------------------+ * OPP1 | | * ---------+ | * | Idle state * +--------------- * * |<- pstate duration ->| * ^ ^ * pts cur_ts */ if (ctx->state != (u32)-1) { /* record pstate after have first cpu_frequency event */ if (!*pts) return 0; delta = cur_ts - *pts; pstate_idx = find_cpu_pstate_idx(*pstate); if (pstate_idx >= MAX_PSTATE_ENTRIES) return 0; key = cpu * MAX_PSTATE_ENTRIES + pstate_idx; val = bpf_map_lookup_elem(&pstate_duration, &key); if (val) __sync_fetch_and_add((long *)val, delta); /* * When state equal to (u32)-1, the cpu just exits from one * specific idle state; for this case we need to record * interval for the pstate. * * OPP2 * -----------+ * | OPP1 * | +----------- * | Idle state | * +---------------------+ * * |<- cstate duration ->| * ^ ^ * cts cur_ts */ } else { key = cpu * MAX_CSTATE_ENTRIES + prev_state; val = bpf_map_lookup_elem(&cstate_duration, &key); if (val) __sync_fetch_and_add((long *)val, delta); } /* Update timestamp for pstate as new start time */ if (*pts) *pts = cur_ts; return 0; } SEC("tracepoint/power/cpu_frequency") int bpf_prog2(struct cpu_args *ctx) { u64 *pts, *cstate, *pstate, prev_state, cur_ts, delta; u32 key, cpu, pstate_idx; u64 *val; cpu = ctx->cpu_id; key = cpu * MAP_OFF_NUM + MAP_OFF_PSTATE_TIME; pts = bpf_map_lookup_elem(&my_map, &key); if (!pts) return 0; key = cpu * MAP_OFF_NUM + MAP_OFF_PSTATE_IDX; pstate = bpf_map_lookup_elem(&my_map, &key); if (!pstate) return 0; key = cpu * MAP_OFF_NUM + MAP_OFF_CSTATE_IDX; cstate = bpf_map_lookup_elem(&my_map, &key); if (!cstate) return 0; prev_state = *pstate; *pstate = ctx->state; if (!*pts) { *pts = bpf_ktime_get_ns(); return 0; } cur_ts = bpf_ktime_get_ns(); delta = cur_ts - *pts; *pts = cur_ts; /* When CPU is in idle, bail out to skip pstate statistics */ if (*cstate != (u32)(-1)) return 0; /* * The cpu changes to another different OPP (in below diagram * change frequency from OPP3 to OPP1), need recording interval * for previous frequency OPP3 and update timestamp as start * time for new frequency OPP1. * * OPP3 * +---------------------+ * OPP2 | | * ---------+ | * | OPP1 * +--------------- * * |<- pstate duration ->| * ^ ^ * pts cur_ts */ pstate_idx = find_cpu_pstate_idx(*pstate); if (pstate_idx >= MAX_PSTATE_ENTRIES) return 0; key = cpu * MAX_PSTATE_ENTRIES + pstate_idx; val = bpf_map_lookup_elem(&pstate_duration, &key); if (val) __sync_fetch_and_add((long *)val, delta); return 0; } char _license[] SEC("license") = "GPL"; u32 _version SEC("version") = LINUX_VERSION_CODE; |