Cache the divide in the hope we can avoid doing it in steady state opteration.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
kernel/sched.c | 2 ++
kernel/sched_debug.c | 1 +
kernel/sched_fair.c | 6 ++----
3 files changed, 5 insertions(+), 4 deletions(-)
Index: linux-2.6-2/kernel/sched.c
===================================================================
--- linux-2.6-2.orig/kernel/sched.c
+++ linux-2.6-2/kernel/sched.c
@@ -1298,11 +1298,13 @@ calc_delta_mine(unsigned long delta_exec
static inline void update_load_add(struct load_weight *lw, unsigned long inc)
{
lw->weight += inc;
+ lw->inv_weight = 0;
}
static inline void update_load_sub(struct load_weight *lw, unsigned long dec)
{
lw->weight -= dec;
+ lw->inv_weight = 0;
}
/*
Index: linux-2.6-2/kernel/sched_debug.c
===================================================================
--- linux-2.6-2.orig/kernel/sched_debug.c
+++ linux-2.6-2/kernel/sched_debug.c
@@ -137,6 +137,7 @@ void print_cfs_rq(struct seq_file *m, in
SPLIT_NS(spread0));
SEQ_printf(m, " .%-30s: %ld\n", "nr_running", cfs_rq->nr_running);
SEQ_printf(m, " .%-30s: %ld\n", "load", cfs_rq->load.weight);
+ SEQ_printf(m, " .%-30s: %ld\n", "load^-1", cfs_rq->load.inv_weight);
#ifdef CONFIG_SCHEDSTATS
SEQ_printf(m, " .%-30s: %d\n", "bkl_count",
rq->bkl_count);
Index: linux-2.6-2/kernel/sched_fair.c
===================================================================
--- linux-2.6-2.orig/kernel/sched_fair.c
+++ linux-2.6-2/kernel/sched_fair.c
@@ -369,10 +369,8 @@ static u64 sched_slice(struct cfs_rq *cf
goto out;
for_each_sched_entity(se) {
- cfs_rq = cfs_rq_of(se);
-
- slice *= se->load.weight;
- do_div(slice, cfs_rq->load.weight);
+ slice = calc_delta_mine(slice,
+ se->load.weight, &cfs_rq_of(se)->load);
}
out:
--
--
