Messages in this thread Patch in this message | | | Date | Wed, 21 Nov 2018 14:08:22 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH v9 09/15] sched: Introduce sched_energy_present static key |
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On Mon, Nov 19, 2018 at 02:18:51PM +0000, Quentin Perret wrote:
> +static void sched_energy_start(int ndoms_new, cpumask_var_t doms_new[]) > +{ > + /* > + * The conditions for EAS to start are checked during the creation of > + * root domains. If one of them meets all conditions, it will have a > + * non-null list of performance domains. > + */ > + while (ndoms_new) { > + if (cpu_rq(cpumask_first(doms_new[ndoms_new - 1]))->rd->pd) > + goto enable; > + ndoms_new--; > + }
That seems quite ugly; can't you simply return a bool from build_perf_domains() ?
Something like the below, but less fugly ;-)
--- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -299,7 +299,7 @@ static void destroy_perf_domain_rcu(stru #define EM_MAX_COMPLEXITY 2048 extern struct cpufreq_governor schedutil_gov; -static void build_perf_domains(const struct cpumask *cpu_map) +static bool build_perf_domains(const struct cpumask *cpu_map) { int i, nr_pd = 0, nr_cs = 0, nr_cpus = cpumask_weight(cpu_map); struct perf_domain *pd = NULL, *tmp; @@ -365,7 +365,7 @@ static void build_perf_domains(const str if (tmp) call_rcu(&tmp->rcu, destroy_perf_domain_rcu); - return; + return !!pd; free: free_pd(pd); @@ -373,6 +373,8 @@ static void build_perf_domains(const str rcu_assign_pointer(rd->pd, NULL); if (tmp) call_rcu(&tmp->rcu, destroy_perf_domain_rcu); + + return false; } #else static void free_pd(struct perf_domain *pd) { } @@ -2173,6 +2175,9 @@ void partition_sched_domains(int ndoms_n } #if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) + { + bool has_eas = false; + /* Build perf. domains: */ for (i = 0; i < ndoms_new; i++) { for (j = 0; j < n && !sched_energy_update; j++) { @@ -2181,10 +2186,13 @@ void partition_sched_domains(int ndoms_n goto match3; } /* No match - add perf. domains for a new rd */ - build_perf_domains(doms_new[i]); + has_eas |= build_perf_domains(doms_new[i]); match3: ; } + + sched_energy_set(has_eas); + } #endif /* Remember the new sched domains: */
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