diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/ext/ext.c | 35 | ||||
| -rw-r--r-- | kernel/sched/ext/internal.h | 16 |
2 files changed, 41 insertions, 10 deletions
diff --git a/kernel/sched/ext/ext.c b/kernel/sched/ext/ext.c index e11c66bd23e7..aca8d2380509 100644 --- a/kernel/sched/ext/ext.c +++ b/kernel/sched/ext/ext.c @@ -5144,6 +5144,7 @@ static const char *scx_cap_names[__SCX_NR_CAPS] = { [__SCX_CAP_ENQ_IMMED] = "enq_immed", [__SCX_CAP_ENQ] = "enq", [__SCX_CAP_PREEMPT] = "preempt", + [__SCX_CAP_PERF] = "perf", }; static ssize_t scx_attr_caps_show(struct kobject *kobj, @@ -9786,6 +9787,7 @@ static s32 scx_cpuperf_set(struct scx_sched *sch, s32 cpu, u32 perf) { struct rq *rq, *locked_rq; struct rq_flags rf; + s32 ret; if (unlikely(perf > SCX_CPUPERF_ONE)) { scx_error(sch, "Invalid cpuperf target %u for CPU %d", perf, cpu); @@ -9816,13 +9818,24 @@ static s32 scx_cpuperf_set(struct scx_sched *sch, s32 cpu, u32 perf) update_rq_clock(rq); } - rq->scx.cpuperf_target = perf; - cpufreq_update_util(rq, 0); + /* + * ecaps updates are folded under the rq lock, making this test + * authoritative: a write can never land after a revoke has taken + * effect on @cpu. + */ + if (likely(!scx_missing_caps(sch, cpu, SCX_CAP_PERF))) { + rq->scx.cpuperf_target = perf; + cpufreq_update_util(rq, 0); + ret = 0; + } else { + __scx_add_event(sch, SCX_EV_SUB_CIDPERF_DENIED, 1); + ret = -EACCES; + } if (!locked_rq) rq_unlock_irqrestore(rq, &rf); - return 0; + return ret; } /** @@ -9859,10 +9872,13 @@ __bpf_kfunc void scx_bpf_cpuperf_set(s32 cpu, u32 perf, const struct bpf_prog_au * @perf: target performance level [0, %SCX_CPUPERF_ONE] * @aux: implicit BPF argument to access bpf_prog_aux hidden from BPF progs * - * cid-addressed equivalent of scx_bpf_cpuperf_set(). + * cid-addressed equivalent of scx_bpf_cpuperf_set(). A sub-sched needs + * SCX_CAP_PERF on @cid. Returns 0 if the target was applied, -%EACCES if + * the write was denied for missing caps, other -errnos if @cid didn't + * resolve. */ -__bpf_kfunc void scx_bpf_cidperf_set(s32 cid, u32 perf, - const struct bpf_prog_aux *aux) +__bpf_kfunc s32 scx_bpf_cidperf_set(s32 cid, u32 perf, + const struct bpf_prog_aux *aux) { struct scx_sched *sch; s32 cpu; @@ -9871,11 +9887,12 @@ __bpf_kfunc void scx_bpf_cidperf_set(s32 cid, u32 perf, sch = scx_prog_sched(aux); if (unlikely(!sch)) - return; + return -ENODEV; cpu = scx_cid_to_cpu(sch, cid); if (cpu < 0) - return; - scx_bpf_cpuperf_set(cpu, perf, aux); + return cpu; + + return scx_cpuperf_set(sch, cpu, perf); } /** diff --git a/kernel/sched/ext/internal.h b/kernel/sched/ext/internal.h index 308d16320818..886f1d132e6b 100644 --- a/kernel/sched/ext/internal.h +++ b/kernel/sched/ext/internal.h @@ -1206,6 +1206,12 @@ struct scx_event_stats { * sub-sched lacked baseline access on the target cid. */ s64 SCX_EV_SUB_REENQ_DENIED; + + /* + * The number of times scx_bpf_cidperf_set() was denied because the + * sub-sched lacked SCX_CAP_PERF on the target cid. + */ + s64 SCX_EV_SUB_CIDPERF_DENIED; }; #define SCX_EVENTS_LIST(SCX_EVENT) \ @@ -1227,7 +1233,8 @@ struct scx_event_stats { SCX_EVENT(SCX_EV_SUB_FORCED_ADMIT); \ SCX_EVENT(SCX_EV_SUB_PREEMPT_DENIED); \ SCX_EVENT(SCX_EV_SUB_KICK_DENIED); \ - SCX_EVENT(SCX_EV_SUB_REENQ_DENIED) + SCX_EVENT(SCX_EV_SUB_REENQ_DENIED); \ + SCX_EVENT(SCX_EV_SUB_CIDPERF_DENIED) struct scx_sched; @@ -1353,6 +1360,11 @@ struct scx_sched_pnode { * - SCX_ENQ_PREEMPT inserts * - SCX_KICK_PREEMPT kicks * + * PERF control the cid's cpu power/perf management state, currently the + * cpufreq target set through scx_bpf_cidperf_set(). Hardware + * control is a separate axis from queue access: PERF neither + * implies nor is implied by the caps above. + * * Implied caps apply to the holder's own use of a cid, not to delegation. * scx_bpf_sub_grant() delegates literally-held caps, so a cap held only through * implication is usable but cannot be re-delegated to a child. When granting a @@ -1363,6 +1375,7 @@ enum scx_cap_flags { __SCX_CAP_ENQ_IMMED = 0, __SCX_CAP_ENQ = 1, __SCX_CAP_PREEMPT = 2, + __SCX_CAP_PERF = 3, __SCX_NR_CAPS, __SCX_CAP_ALL = BIT_U64(__SCX_NR_CAPS) - 1, @@ -1370,6 +1383,7 @@ enum scx_cap_flags { SCX_CAP_ENQ_IMMED = BIT_U64(__SCX_CAP_ENQ_IMMED), SCX_CAP_ENQ = BIT_U64(__SCX_CAP_ENQ), SCX_CAP_PREEMPT = BIT_U64(__SCX_CAP_PREEMPT), + SCX_CAP_PERF = BIT_U64(__SCX_CAP_PERF), /* alias for minimal cap to make any use of a cpu */ SCX_CAP_BASE = SCX_CAP_ENQ_IMMED, |