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-rw-r--r--kernel/sched/fair.c21
1 files changed, 13 insertions, 8 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index e148571..8c381a6 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2603,6 +2603,16 @@ static const u32 runnable_avg_yN_sum[] = {
};
/*
+ * 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)
*/
@@ -2650,14 +2660,9 @@ static u32 __compute_runnable_contrib(u64 n)
else if (unlikely(n >= LOAD_AVG_MAX_N))
return LOAD_AVG_MAX;
- /* Compute \Sum k^n combining precomputed values for k^i, \Sum k^j */
- do {
- contrib /= 2; /* y^LOAD_AVG_PERIOD = 1/2 */
- contrib += runnable_avg_yN_sum[LOAD_AVG_PERIOD];
-
- n -= LOAD_AVG_PERIOD;
- } while (n > LOAD_AVG_PERIOD);
-
+ /* Since n < LOAD_AVG_MAX_N, n/LOAD_AVG_PERIOD < 11 */
+ contrib = __accumulated_sum_N32[n/LOAD_AVG_PERIOD];
+ n %= LOAD_AVG_PERIOD;
contrib = decay_load(contrib, n);
return contrib + runnable_avg_yN_sum[n];
}