sched: make the multiplication table more accurate

do small deltas in the weight and multiplication constant table so that the worst-case numeric error is better than 1:100000000. (8 digits) the current error table is: nice mult * inv_mult error ------------------------------------------ -20: 88761 * 48388 -0.0000000065 -19: 71755 * 59856 -0.0000000037 -18: 56483 * 76040 0.0000000056 -17: 46273 * 92818 0.0000000042 -16: 36291 * 118348 -0.0000000065 -15: 29154 * 147320 -0.0000000037 -14: 23254 * 184698 -0.0000000009 -13: 18705 * 229616 -0.0000000037 -12: 14949 * 287308 -0.0000000009 -11: 11916 * 360437 -0.0000000009 -10: 9548 * 449829 -0.0000000009 -9: 7620 * 563644 -0.0000000037 -8: 6100 * 704093 0.0000000009 -7: 4904 * 875809 0.0000000093 -6: 3906 * 1099582 -0.0000000009 -5: 3121 * 1376151 -0.0000000058 -4: 2501 * 1717300 0.0000000009 -3: 1991 * 2157191 -0.0000000035 -2: 1586 * 2708050 0.0000000009 -1: 1277 * 3363326 0.0000000014 0: 1024 * 4194304 0.0000000000 1: 820 * 5237765 0.0000000009 2: 655 * 6557202 0.0000000033 3: 526 * 8165337 -0.0000000079 4: 423 * 10153587 0.0000000012 5: 335 * 12820798 0.0000000079 6: 272 * 15790321 0.0000000037 7: 215 * 19976592 -0.0000000037 8: 172 * 24970740 -0.0000000037 9: 137 * 31350126 -0.0000000079 10: 110 * 39045157 -0.0000000061 11: 87 * 49367440 -0.0000000037 12: 70 * 61356676 0.0000000056 13: 56 * 76695844 -0.0000000075 14: 45 * 95443717 -0.0000000072 15: 36 * 119304647 -0.0000000009 16: 29 * 148102320 -0.0000000037 17: 23 * 186737708 -0.0000000028 18: 18 * 238609294 -0.0000000009 19: 15 * 286331153 -0.0000000002 Signed-off-by: Ingo Molnar <mingo@elte.hu>
git-mirror · Aug 9, 2007 · 254753d · 254753d
1 parent 6e82a3b
commit 254753d
Showing 1 changed file with 16 additions and 13 deletions.
diff --git a/kernel/sched.c b/kernel/sched.c
@@ -704,11 +704,14 @@ static void update_load_sub(struct load_weight *lw, unsigned long dec)
  * the relative distance between them is ~25%.)
  */
 static const int prio_to_weight[40] = {
-/* -20 */ 88818, 71054, 56843, 45475, 36380, 29104, 23283, 18626, 14901, 11921,
-/* -10 */  9537,  7629,  6103,  4883,  3906,  3125,  2500,  2000,  1600,  1280,
-/*   0 */  NICE_0_LOAD /* 1024 */,
-/*   1 */          819,   655,   524,   419,   336,   268,   215,   172,   137,
-/*  10 */   110,    87,    70,    56,    45,    36,    29,    23,    18,    15,
+ /* -20 */     88761,     71755,     56483,     46273,     36291,
+ /* -15 */     29154,     23254,     18705,     14949,     11916,
+ /* -10 */      9548,      7620,      6100,      4904,      3906,
+ /*  -5 */      3121,      2501,      1991,      1586,      1277,
+ /*   0 */      1024,       820,       655,       526,       423,
+ /*   5 */       335,       272,       215,       172,       137,
+ /*  10 */       110,        87,        70,        56,        45,
+ /*  15 */        36,        29,        23,        18,        15,
 };
 
 /*
@@ -719,14 +722,14 @@ static const int prio_to_weight[40] = {
  * into multiplications:
  */
 static const u32 prio_to_wmult[40] = {
-/* -20 */     48356,     60446,     75558,     94446,    118058,
-/* -15 */    147573,    184467,    230589,    288233,    360285,
-/* -10 */    450347,    562979,    703746,    879575,   1099582,
-/*  -5 */   1374389,   1717986,   2147483,   2684354,   3355443,
-/*   0 */   4194304,   5244160,   6557201,   8196502,  10250518,
-/*   5 */  12782640,  16025997,  19976592,  24970740,  31350126,
-/*  10 */  39045157,  49367440,  61356675,  76695844,  95443717,
-/*  15 */ 119304647, 148102320, 186737708, 238609294, 286331153,
+ /* -20 */     48388,     59856,     76040,     92818,    118348,
+ /* -15 */    147320,    184698,    229616,    287308,    360437,
+ /* -10 */    449829,    563644,    704093,    875809,   1099582,
+ /*  -5 */   1376151,   1717300,   2157191,   2708050,   3363326,
+ /*   0 */   4194304,   5237765,   6557202,   8165337,  10153587,
+ /*   5 */  12820798,  15790321,  19976592,  24970740,  31350126,
+ /*  10 */  39045157,  49367440,  61356676,  76695844,  95443717,
+ /*  15 */ 119304647, 148102320, 186737708, 238609294, 286331153,
 };
 
 static void activate_task(struct rq *rq, struct task_struct *p, int wakeup);