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authorIngo Molnar <mingo@elte.hu>2007-08-24 18:39:10 (GMT)
committerIngo Molnar <mingo@elte.hu>2007-08-24 18:39:10 (GMT)
commitb2133c8b1e270b4a7c36f70e29be8738d09e850b (patch)
tree9075055664141cc1b91a0b3eac915e6241e38801 /kernel/sched_fair.c
parent98fbc798533339be802c6dcd48c2293c712e87db (diff)
downloadlinux-b2133c8b1e270b4a7c36f70e29be8738d09e850b.tar.xz
sched: tidy up and simplify the bonus balance
make the bonus balance more consistent: do not hand out a bonus if there's too much in flight already, and only deduct as much from a runner as it has the capacity. This makes the bonus engine a zero-sum game (as intended). this also simplifies the code: text data bss dec hex filename 34770 2998 24 37792 93a0 sched.o.before 34749 2998 24 37771 938b sched.o.after and it also avoids overscheduling in sleep-happy workloads like hackbench.c. Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched_fair.c')
-rw-r--r--kernel/sched_fair.c14
1 files changed, 10 insertions, 4 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 6b0974c..c578370 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -306,6 +306,8 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr)
delta = min(cfs_rq->sleeper_bonus, (u64)delta_exec);
delta = calc_delta_mine(delta, curr->load.weight, lw);
delta = min((u64)delta, cfs_rq->sleeper_bonus);
+ delta = min(delta, (unsigned long)(
+ (long)sysctl_sched_runtime_limit - curr->wait_runtime));
cfs_rq->sleeper_bonus -= delta;
delta_mine -= delta;
}
@@ -493,6 +495,13 @@ static void __enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
unsigned long load = cfs_rq->load.weight, delta_fair;
long prev_runtime;
+ /*
+ * Do not boost sleepers if there's too much bonus 'in flight'
+ * already:
+ */
+ if (unlikely(cfs_rq->sleeper_bonus > sysctl_sched_runtime_limit))
+ return;
+
if (sysctl_sched_features & SCHED_FEAT_SLEEPER_LOAD_AVG)
load = rq_of(cfs_rq)->cpu_load[2];
@@ -512,16 +521,13 @@ static void __enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
prev_runtime = se->wait_runtime;
__add_wait_runtime(cfs_rq, se, delta_fair);
+ schedstat_add(cfs_rq, wait_runtime, se->wait_runtime);
delta_fair = se->wait_runtime - prev_runtime;
/*
* Track the amount of bonus we've given to sleepers:
*/
cfs_rq->sleeper_bonus += delta_fair;
- if (unlikely(cfs_rq->sleeper_bonus > sysctl_sched_runtime_limit))
- cfs_rq->sleeper_bonus = sysctl_sched_runtime_limit;
-
- schedstat_add(cfs_rq, wait_runtime, se->wait_runtime);
}
static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)