Re: [PATCH v2 4/7] sched: powerpc: create a dedicated topology table

On 03/18/2014 11:26 PM, Vincent Guittot wrote:

Create a dedicated topology table for handling asymetric feature of powerpc.

Signed-off-by: Vincent Guittot vincent.guittot@linaro.org

arch/powerpc/kernel/smp.c | 31 +++++++++++++++++++++++-------- include/linux/sched.h | 2 -- kernel/sched/core.c | 6 ------ 3 files changed, 23 insertions(+), 16 deletions(-)

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index ac2621a..c9cade5 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -755,6 +755,28 @@ int setup_profiling_timer(unsigned int multiplier) return 0; }

+#ifdef CONFIG_SCHED_SMT +/* cpumask of CPUs with asymetric SMT dependancy */ +static const int powerpc_smt_flags(void) +{

• int flags = SD_SHARE_CPUPOWER | SD_SHARE_PKG_RESOURCES;
• if (cpu_has_feature(CPU_FTR_ASYM_SMT)) {

• printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n");
  

• flags |= SD_ASYM_PACKING;
  

• }
• return flags;

+} +#endif

+static struct sched_domain_topology_level powerpc_topology[] = { +#ifdef CONFIG_SCHED_SMT

• { cpu_smt_mask, powerpc_smt_flags, SD_INIT_NAME(SMT) },

+#endif

• { cpu_cpu_mask, SD_INIT_NAME(DIE) },
• { NULL, },

+};

void __init smp_cpus_done(unsigned int max_cpus) { cpumask_var_t old_mask; @@ -779,15 +801,8 @@ void __init smp_cpus_done(unsigned int max_cpus)

dump_numa_cpu_topology();

-}

• set_sched_topology(powerpc_topology);

-int arch_sd_sibling_asym_packing(void) -{

• if (cpu_has_feature(CPU_FTR_ASYM_SMT)) {

• printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n");
  

• return SD_ASYM_PACKING;
  

• }
• return 0;

}

#ifdef CONFIG_HOTPLUG_CPU diff --git a/include/linux/sched.h b/include/linux/sched.h index 4db592a..6479de4 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -868,8 +868,6 @@ enum cpu_idle_type { #define SD_OVERLAP 0x2000 /* sched_domains of this level overlap */ #define SD_NUMA 0x4000 /* cross-node balancing */

-extern int __weak arch_sd_sibiling_asym_packing(void);

#ifdef CONFIG_SCHED_SMT static inline const int cpu_smt_flags(void) { diff --git a/kernel/sched/core.c b/kernel/sched/core.c index f2bfa76..0b51ee3 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5833,11 +5833,6 @@ static void init_sched_groups_power(int cpu, struct sched_domain *sd) atomic_set(&sg->sgp->nr_busy_cpus, sg->group_weight); }

-int __weak arch_sd_sibling_asym_packing(void) -{

•   return 0*SD_ASYM_PACKING;
  

-}

/*

• Initializers for schedule domains
• Non-inlined to reduce accumulated stack pressure in build_sched_domains()

@@ -6018,7 +6013,6 @@ sd_init(struct sched_domain_topology_level *tl, int cpu) if (sd->flags & SD_SHARE_CPUPOWER) { sd->imbalance_pct = 110; sd->smt_gain = 1178; /* ~15% */

• sd->flags |= arch_sd_sibling_asym_packing();
  
  

  } else if (sd->flags & SD_SHARE_PKG_RESOURCES) { sd->imbalance_pct = 117;

Reviewed-by: Preeti U Murthy preeti@linux.vnet.ibm.com