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

From: Vincent Guittot
Date: Tue Mar 18 2014 - 13:59:17 EST


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

Signed-off-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
---
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;
--
1.9.0

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