[PATCH v2 12/13] arm: Set SD_ASYM_CPUCAPACITY for big.LITTLE platforms

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From	Morten Rasmussen <morten.rasmussen@arm.com>
Newsgroups	linux.kernel
Subject	[PATCH v2 12/13] arm: Set SD_ASYM_CPUCAPACITY for big.LITTLE platforms
Date	Wed, 22 Jun 2016 19:10:03 +0200
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Set the SD_ASYM_CPUCAPACITY flag for DIE and MC level sched_domains
on big.LITTLE systems.

cc: Russell King <linux@arm.linux.org.uk>

Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
---
 arch/arm/kernel/topology.c | 23 ++++++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
index ec279d161b32..ab6d9c1835a4 100644
--- a/arch/arm/kernel/topology.c
+++ b/arch/arm/kernel/topology.c
@@ -78,6 +78,7 @@ static unsigned long *__cpu_capacity;
 #define cpu_capacity(cpu)	__cpu_capacity[cpu]
 
 static unsigned long middle_capacity = 1;
+static unsigned int big_little;
 
 /*
  * Iterate all CPUs' descriptor in DT and compute the efficiency
@@ -151,6 +152,8 @@ static void __init parse_dt_topology(void)
 		middle_capacity = ((max_capacity / 3)
 				>> (SCHED_CAPACITY_SHIFT-1)) + 1;
 
+	if (max_capacity && max_capacity != min_capacity)
+		big_little = 1;
 }
 
 /*
@@ -277,15 +280,29 @@ void store_cpu_topology(unsigned int cpuid)
 
 static inline int cpu_corepower_flags(void)
 {
-	return SD_SHARE_PKG_RESOURCES  | SD_SHARE_POWERDOMAIN;
+	int flags = SD_SHARE_PKG_RESOURCES | SD_SHARE_POWERDOMAIN;
+
+	return big_little ? SD_ASYM_CPUCAPACITY | flags : flags;
+}
+
+static inline int arm_cpu_core_flags(void)
+{
+	int flags = SD_SHARE_PKG_RESOURCES;
+
+	return big_little ? SD_ASYM_CPUCAPACITY | flags : flags;
+}
+
+static inline int arm_cpu_cpu_flags(void)
+{
+	return big_little ? SD_ASYM_CPUCAPACITY : 0;
 }
 
 static struct sched_domain_topology_level arm_topology[] = {
 #ifdef CONFIG_SCHED_MC
 	{ cpu_corepower_mask, cpu_corepower_flags, SD_INIT_NAME(GMC) },
-	{ cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) },
+	{ cpu_coregroup_mask, arm_cpu_core_flags, SD_INIT_NAME(MC) },
 #endif
-	{ cpu_cpu_mask, SD_INIT_NAME(DIE) },
+	{ cpu_cpu_mask, arm_cpu_cpu_flags, SD_INIT_NAME(DIE) },
 	{ NULL, },
 };
 
-- 
1.9.1

Thread

[PATCH v2 00/13] sched: Clean-ups and asymmetric cpu capacity support Morten Rasmussen <morten.rasmussen@arm.com> - 2016-06-22 19:10 +0200
  [PATCH v2 11/13] sched/fair: Avoid pulling tasks from non-overloaded higher capacity groups Morten Rasmussen <morten.rasmussen@arm.com> - 2016-06-22 19:10 +0200
  [PATCH v2 09/13] sched/fair: Consider spare capacity in find_idlest_group() Morten Rasmussen <morten.rasmussen@arm.com> - 2016-06-22 19:10 +0200
  [PATCH v2 12/13] arm: Set SD_ASYM_CPUCAPACITY for big.LITTLE platforms Morten Rasmussen <morten.rasmussen@arm.com> - 2016-06-22 19:10 +0200
  [PATCH v2 05/13] sched: Enable SD_BALANCE_WAKE for asymmetric capacity systems Morten Rasmussen <morten.rasmussen@arm.com> - 2016-06-22 19:10 +0200

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