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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-10-22 18:07:48 +0530 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2009-10-29 09:08:24 +0100 |
| commit | 56e9147752899a49b54186ad064cbeb36cd159a4 (patch) | |
| tree | b2c276dba9ab0c02033712ead742b05191abede0 /kernel | |
| parent | 581d1c646e0504492bff3e97a113eba7ec8b40a3 (diff) | |
| download | lwn-56e9147752899a49b54186ad064cbeb36cd159a4.tar.gz lwn-56e9147752899a49b54186ad064cbeb36cd159a4.zip | |
sched: dynamic cpu_power
Recompute the cpu_power for each cpu during load-balance
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Dinakar Guniguntala <dino@in.ibm.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Darren Hart <dvhltc@us.ibm.com>
Cc: John Kacur <jkacur@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched.c | 38 |
1 files changed, 35 insertions, 3 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 9c750e363b96..5061d8627d8c 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -3780,14 +3780,46 @@ static inline int check_power_save_busiest_group(struct sd_lb_stats *sds, } #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ -static void update_sched_power(struct sched_domain *sd) +unsigned long __weak arch_smt_gain(struct sched_domain *sd, int cpu) +{ + unsigned long weight = cpumask_weight(sched_domain_span(sd)); + unsigned long smt_gain = sd->smt_gain; + + smt_gain /= weight; + + return smt_gain; +} + +static void update_cpu_power(struct sched_domain *sd, int cpu) +{ + unsigned long weight = cpumask_weight(sched_domain_span(sd)); + unsigned long power = SCHED_LOAD_SCALE; + struct sched_group *sdg = sd->groups; + unsigned long old = sdg->__cpu_power; + + /* here we could scale based on cpufreq */ + + if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) { + power *= arch_smt_gain(sd, cpu); + power >>= SCHED_LOAD_SHIFT; + } + + /* here we could scale based on RT time */ + + if (power != old) { + sdg->__cpu_power = power; + sdg->reciprocal_cpu_power = reciprocal_value(power); + } +} + +static void update_group_power(struct sched_domain *sd, int cpu) { struct sched_domain *child = sd->child; struct sched_group *group, *sdg = sd->groups; unsigned long power = sdg->__cpu_power; if (!child) { - /* compute cpu power for this cpu */ + update_cpu_power(sd, cpu); return; } @@ -3830,7 +3862,7 @@ static inline void update_sg_lb_stats(struct sched_domain *sd, if (local_group) { balance_cpu = group_first_cpu(group); if (balance_cpu == this_cpu) - update_sched_power(sd); + update_group_power(sd, this_cpu); } /* Tally up the load of all CPUs in the group */ |