diff options
| -rw-r--r-- | kernel/sched/tune.c | 77 |
1 files changed, 39 insertions, 38 deletions
diff --git a/kernel/sched/tune.c b/kernel/sched/tune.c index afc4a7747161..6d5fbde9c70e 100644 --- a/kernel/sched/tune.c +++ b/kernel/sched/tune.c @@ -51,50 +51,51 @@ __schedtune_accept_deltas(int nrg_delta, int cap_delta, int perf_boost_idx, int perf_constrain_idx) { int payoff = -INT_MAX; + int gain_idx = -1; /* Performance Boost (B) region */ - if (nrg_delta > 0 && cap_delta > 0) { - /* - * Evaluate "Performance Boost" vs "Energy Increase" - * payoff criteria: - * cap_delta / nrg_delta < cap_gain / nrg_gain - * which is: - * nrg_delta * cap_gain > cap_delta * nrg_gain - */ - payoff = nrg_delta * threshold_gains[perf_boost_idx].cap_gain; - payoff -= cap_delta * threshold_gains[perf_boost_idx].nrg_gain; - - trace_sched_tune_filter( - nrg_delta, cap_delta, - threshold_gains[perf_boost_idx].nrg_gain, - threshold_gains[perf_boost_idx].cap_gain, - payoff, 8); - - return payoff; - } - + if (nrg_delta >= 0 && cap_delta > 0) + gain_idx = perf_boost_idx; /* Performance Constraint (C) region */ - if (nrg_delta < 0 && cap_delta < 0) { - /* - * Evaluate "Performance Boost" vs "Energy Increase" - * payoff criteria: - * cap_delta / nrg_delta > cap_gain / nrg_gain - * which is: - * cap_delta * nrg_gain > nrg_delta * cap_gain - */ - payoff = cap_delta * threshold_gains[perf_constrain_idx].nrg_gain; - payoff -= nrg_delta * threshold_gains[perf_constrain_idx].cap_gain; - - trace_sched_tune_filter( - nrg_delta, cap_delta, - threshold_gains[perf_constrain_idx].nrg_gain, - threshold_gains[perf_constrain_idx].cap_gain, - payoff, 6); + else if (nrg_delta < 0 && cap_delta <= 0) + gain_idx = perf_constrain_idx; + /* Default: reject schedule candidate */ + if (gain_idx == -1) return payoff; - } - /* Default: reject schedule candidate */ + /* + * Evaluate "Performance Boost" vs "Energy Increase" + * + * - Performance Boost (B) region + * + * Condition: nrg_delta > 0 && cap_delta > 0 + * Payoff criteria: + * cap_gain / nrg_gain < cap_delta / nrg_delta = + * cap_gain * nrg_delta < cap_delta * nrg_gain + * Note that since both nrg_gain and nrg_delta are positive, the + * inequality does not change. Thus: + * + * payoff = (cap_delta * nrg_gain) - (cap_gain * nrg_delta) + * + * - Performance Constraint (C) region + * + * Condition: nrg_delta < 0 && cap_delta < 0 + * payoff criteria: + * cap_gain / nrg_gain > cap_delta / nrg_delta = + * cap_gain * nrg_delta < cap_delta * nrg_gain + * Note that since nrg_gain > 0 while nrg_delta < 0, the + * inequality change. Thus: + * + * payoff = (cap_delta * nrg_gain) - (cap_gain * nrg_delta) + * + * This means that, in case of same positive defined {cap,nrg}_gain + * for both the B and C regions, we can use the same payoff formula + * where a positive value represents the accept condition. + */ + payoff = cap_delta * threshold_gains[gain_idx].nrg_gain; + payoff -= nrg_delta * threshold_gains[gain_idx].cap_gain; + return payoff; } |