diff options
| -rw-r--r-- | kernel/sched/fair.c | 75 |
1 files changed, 19 insertions, 56 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 76f67b3e34d6..1e5f58081762 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -727,7 +727,6 @@ static unsigned long task_h_load(struct task_struct *p); */ #define LOAD_AVG_PERIOD 32 #define LOAD_AVG_MAX 47742 /* maximum possible load avg */ -#define LOAD_AVG_MAX_N 345 /* number of full periods to produce LOAD_AVG_MAX */ /* Give new sched_entity start runnable values to heavy its load in infant time */ void init_entity_runnable_average(struct sched_entity *se) @@ -2744,26 +2743,6 @@ static const u32 runnable_avg_yN_inv[] = { }; /* - * Precomputed \Sum y^k { 1<=k<=n }. These are floor(true_value) to prevent - * over-estimates when re-combining. - */ -static const u32 runnable_avg_yN_sum[] = { - 0, 1002, 1982, 2941, 3880, 4798, 5697, 6576, 7437, 8279, 9103, - 9909,10698,11470,12226,12966,13690,14398,15091,15769,16433,17082, - 17718,18340,18949,19545,20128,20698,21256,21802,22336,22859,23371, -}; - -/* - * Precomputed \Sum y^k { 1<=k<=n, where n%32=0). Values are rolled down to - * lower integers. See Documentation/scheduler/sched-avg.txt how these - * were generated: - */ -static const u32 __accumulated_sum_N32[] = { - 0, 23371, 35056, 40899, 43820, 45281, - 46011, 46376, 46559, 46650, 46696, 46719, -}; - -/* * Approximate: * val * y^n, where y^32 ~= 0.5 (~1 scheduling period) */ @@ -2771,9 +2750,7 @@ static u64 decay_load(u64 val, u64 n) { unsigned int local_n; - if (!n) - return val; - else if (unlikely(n > LOAD_AVG_PERIOD * 63)) + if (unlikely(n > LOAD_AVG_PERIOD * 63)) return 0; /* after bounds checking we can collapse to 32-bit */ @@ -2795,40 +2772,25 @@ static u64 decay_load(u64 val, u64 n) return val; } -static u32 __accumulate_sum(u64 periods, u32 period_contrib, u32 remainder) +static u32 __accumulate_pelt_segments(u64 periods, u32 d1, u32 d3) { - u32 c1, c2, c3 = remainder; /* y^0 == 1 */ - - if (!periods) - return remainder - period_contrib; - - if (unlikely(periods >= LOAD_AVG_MAX_N)) - return LOAD_AVG_MAX; + u32 c1, c2, c3 = d3; /* y^0 == 1 */ /* * c1 = d1 y^(p+1) */ - c1 = decay_load((u64)(1024 - period_contrib), periods); + c1 = decay_load((u64)d1, periods); - periods -= 1; /* - * For updates fully spanning n periods, the contribution to runnable - * average will be: + * p + * c2 = 1024 \Sum y^n + * n=1 * - * c2 = 1024 \Sum y^n - * - * We can compute this reasonably efficiently by combining: - * - * y^PERIOD = 1/2 with precomputed 1024 \Sum y^n {for: n < PERIOD} + * inf inf + * = 1024 ( \Sum y^n - \Sum y^n - y^0 ) + * n=0 n=p+1 */ - if (likely(periods <= LOAD_AVG_PERIOD)) { - c2 = runnable_avg_yN_sum[periods]; - } else { - c2 = __accumulated_sum_N32[periods/LOAD_AVG_PERIOD]; - periods %= LOAD_AVG_PERIOD; - c2 = decay_load(c2, periods); - c2 += runnable_avg_yN_sum[periods]; - } + c2 = LOAD_AVG_MAX - decay_load(LOAD_AVG_MAX, periods) - 1024; return c1 + c2 + c3; } @@ -2861,8 +2823,8 @@ accumulate_sum(u64 delta, int cpu, struct sched_avg *sa, unsigned long weight, int running, struct cfs_rq *cfs_rq) { unsigned long scale_freq, scale_cpu; + u32 contrib = (u32)delta; /* p == 0 -> delta < 1024 */ u64 periods; - u32 contrib; scale_freq = arch_scale_freq_capacity(NULL, cpu); scale_cpu = arch_scale_cpu_capacity(NULL, cpu); @@ -2880,13 +2842,14 @@ accumulate_sum(u64 delta, int cpu, struct sched_avg *sa, decay_load(cfs_rq->runnable_load_sum, periods); } sa->util_sum = decay_load((u64)(sa->util_sum), periods); - } - /* - * Step 2 - */ - delta %= 1024; - contrib = __accumulate_sum(periods, sa->period_contrib, delta); + /* + * Step 2 + */ + delta %= 1024; + contrib = __accumulate_pelt_segments(periods, + 1024 - sa->period_contrib, delta); + } sa->period_contrib = delta; contrib = cap_scale(contrib, scale_freq); |