From 37ed2d7007a65874850f3e357c095806c3756330 Mon Sep 17 00:00:00 2001 From: Mike Galbraith Date: Wed, 4 Nov 2009 17:53:50 +0100 Subject: [PATCH] sched: Rate-limit newidle commit 1b9508f6831e10d53256825de8904caa22d1ca2c upstream. Rate limit newidle to migration_cost. It's a win for all stages of sysbench oltp tests. Signed-off-by: Mike Galbraith Cc: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- kernel/sched.c | 22 +++++++++++++++++++++- kernel/sched_debug.c | 4 ++++ 2 files changed, 25 insertions(+), 1 deletion(-) diff --git a/kernel/sched.c b/kernel/sched.c index 3c11ae0a948d..88acc79f5897 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -591,6 +591,8 @@ struct rq { u64 rt_avg; u64 age_stamp; + u64 idle_stamp; + u64 avg_idle; #endif /* calc_load related fields */ @@ -2384,6 +2386,17 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, if (rq != orig_rq) update_rq_clock(rq); + if (rq->idle_stamp) { + u64 delta = rq->clock - rq->idle_stamp; + u64 max = 2*sysctl_sched_migration_cost; + + if (delta > max) + rq->avg_idle = max; + else + update_avg(&rq->avg_idle, delta); + rq->idle_stamp = 0; + } + WARN_ON(p->state != TASK_WAKING); cpu = task_cpu(p); @@ -4429,6 +4442,11 @@ static void idle_balance(int this_cpu, struct rq *this_rq) int pulled_task = 0; unsigned long next_balance = jiffies + HZ; + this_rq->idle_stamp = this_rq->clock; + + if (this_rq->avg_idle < sysctl_sched_migration_cost) + return; + for_each_domain(this_cpu, sd) { unsigned long interval; @@ -4443,8 +4461,10 @@ static void idle_balance(int this_cpu, struct rq *this_rq) interval = msecs_to_jiffies(sd->balance_interval); if (time_after(next_balance, sd->last_balance + interval)) next_balance = sd->last_balance + interval; - if (pulled_task) + if (pulled_task) { + this_rq->idle_stamp = 0; break; + } } if (pulled_task || time_after(jiffies, this_rq->next_balance)) { /* diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c index efb84409bc43..6988cf08f705 100644 --- a/kernel/sched_debug.c +++ b/kernel/sched_debug.c @@ -285,12 +285,16 @@ static void print_cpu(struct seq_file *m, int cpu) #ifdef CONFIG_SCHEDSTATS #define P(n) SEQ_printf(m, " .%-30s: %d\n", #n, rq->n); +#define P64(n) SEQ_printf(m, " .%-30s: %Ld\n", #n, rq->n); P(yld_count); P(sched_switch); P(sched_count); P(sched_goidle); +#ifdef CONFIG_SMP + P64(avg_idle); +#endif P(ttwu_count); P(ttwu_local); -- 2.34.1