struct uclamp_rq was zeroed out entirely in assumption that in the first call to uclamp_rq_inc() they'd be initialized correctly in accordance to default settings. But when next patch introduces a static key to skip uclamp_rq_{inc,dec}() until userspace opts in to use uclamp, schedutil will fail to perform any frequency changes because the rq->uclamp[UCLAMP_MAX].value is zeroed at init and stays as such. Which means all rqs are capped to 0 by default. Fix it by making sure we do proper initialization at init without relying on uclamp_rq_inc() doing it later.
Unified · Split
| @@ -1239,6 +1239,20 @@ static void uclamp_fork(struct task_struct *p) · 1238 unmodified lines | ||
| 1239 | 1239 | } |
| 1240 | 1240 | } |
| 1241 | 1241 | |
| 1242 | +static void __init init_uclamp_rq(struct rq *rq) | |
| 1243 | +{ | |
| 1244 | + enum uclamp_id clamp_id; | |
| 1245 | + struct uclamp_rq *uc_rq = rq->uclamp; | |
| 1246 | + | |
| 1247 | + for_each_clamp_id(clamp_id) { | |
| 1248 | + uc_rq[clamp_id] = (struct uclamp_rq) { | |
| 1249 | + .value = uclamp_none(clamp_id) | |
| 1250 | + }; | |
| 1251 | + } | |
| 1252 | + | |
| 1253 | + rq->uclamp_flags = 0; | |
| 1254 | +} | |
| 1255 | + | |
| 1242 | 1256 | static void __init init_uclamp(void) |
| 1243 | 1257 | { |
| 1244 | 1258 | struct uclamp_se uc_max = {}; |
| @@ -1247,11 +1261,8 @@ static void __init init_uclamp(void) · 2 unmodified lines | ||
| 1247 | 1261 | |
| 1248 | 1262 | mutex_init(&uclamp_mutex); |
| 1249 | 1263 | |
| 1250 | − for_each_possible_cpu(cpu) { | |
| 1251 | − memset(&cpu_rq(cpu)->uclamp, 0, | |
| 1252 | − sizeof(struct uclamp_rq)*UCLAMP_CNT); | |
| 1253 | − cpu_rq(cpu)->uclamp_flags = 0; | |
| 1254 | − } | |
| 1264 | + for_each_possible_cpu(cpu) | |
| 1265 | + init_uclamp_rq(cpu_rq(cpu)); | |
| 1255 | 1266 | |
| 1256 | 1267 | for_each_clamp_id(clamp_id) { |
| 1257 | 1268 | uclamp_se_set(&init_task.uclamp_req[clamp_id], |