From: Ingo Molnar Date: Fri, 24 Aug 2007 18:39:10 +0000 (+0200) Subject: sched: tidy up and simplify the bonus balance X-Git-Tag: v2.6.23-rc4~17^2~3 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b2133c8b1e270b4a7c36f70e29be8738d09e850b;p=linux-2.6 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 --- diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 6b0974c3fb..c578370cd6 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)