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| author | Ingo Molnar <mingo@elte.hu> | 2007-07-16 09:46:30 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2007-07-16 09:46:30 +0200 |
| commit | f9153ee6c71cb9ab38de3b8ed66b1c3fa27c3f7d (patch) | |
| tree | 77a00afe63230a59f7e10cd034eb467bbb1d5430 /kernel | |
| parent | 5926c50b83b626991c8c38efbca2020ee96b215f (diff) | |
| download | kernel_samsung_smdk4412-f9153ee6c71cb9ab38de3b8ed66b1c3fa27c3f7d.zip kernel_samsung_smdk4412-f9153ee6c71cb9ab38de3b8ed66b1c3fa27c3f7d.tar.gz kernel_samsung_smdk4412-f9153ee6c71cb9ab38de3b8ed66b1c3fa27c3f7d.tar.bz2 | |
[PATCH] sched: improve weight-array comments
improve the comments around the wmult array (which controls the weight
of niced tasks). Clarify that to achieve a 10% difference in CPU
utilization, a weight multiplier of 1.25 has to be used.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 3332bbb..a7284bc 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -736,7 +736,9 @@ static void update_curr_load(struct rq *rq, u64 now) * * The "10% effect" is relative and cumulative: from _any_ nice level, * if you go up 1 level, it's -10% CPU usage, if you go down 1 level - * it's +10% CPU usage. + * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25. + * If a task goes up by ~10% and another task goes down by ~10% then + * 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, |