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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2008-04-19 19:45:00 +0200
committerIngo Molnar <mingo@elte.hu>2008-04-19 19:45:00 +0200
commit8f1bc385cfbab474db6c27b5af1e439614f3025c (patch)
treee4cfb8255d62621d17bc08ee5f94f42a0cc22677 /kernel/sched.c
parentsched: fair-group: de-couple load-balancing from the rb-trees (diff)
downloadlinux-8f1bc385cfbab474db6c27b5af1e439614f3025c.tar.xz
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sched: fair: weight calculations
In order to level the hierarchy, we need to calculate load based on the root view. That is, each task's load is in the same unit. A / \ B 1 / \ 2 3 To compute 1's load we do: weight(1) -------------- rq_weight(A) To compute 2's load we do: weight(2) weight(B) ------------ * ----------- rq_weight(B) rw_weight(A) This yields load fractions in comparable units. The consequence is that it changes virtual time. We used to have: time_{i} vtime_{i} = ------------ weight_{i} vtime = \Sum vtime_{i} = time / rq_weight. But with the new way of load calculation we get that vtime equals time. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched.c')
-rw-r--r--kernel/sched.c9
1 files changed, 3 insertions, 6 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 3202462109f5..6d55dfc56cab 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1320,6 +1320,9 @@ static void __resched_task(struct task_struct *p, int tif_bit)
*/
#define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y))
+/*
+ * delta *= weight / lw
+ */
static unsigned long
calc_delta_mine(unsigned long delta_exec, unsigned long weight,
struct load_weight *lw)
@@ -1342,12 +1345,6 @@ calc_delta_mine(unsigned long delta_exec, unsigned long weight,
return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX);
}
-static inline unsigned long
-calc_delta_fair(unsigned long delta_exec, struct load_weight *lw)
-{
- return calc_delta_mine(delta_exec, NICE_0_LOAD, lw);
-}
-
static inline void update_load_add(struct load_weight *lw, unsigned long inc)
{
lw->weight += inc;