linux-kernel - [RFC PATCH v3 6/6] ARM: sched: clear SD_SHARE

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Date:	Fri, 22 Mar 2013 13:25:55 +0100
From:	Vincent Guittot <vincent.guittot@...aro.org>
To:	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	linaro-kernel@...ts.linaro.org, peterz@...radead.org,
	mingo@...nel.org, linux@....linux.org.uk, pjt@...gle.com,
	santosh.shilimkar@...com, morten.rasmussen@....com,
	chander.kashyap@...aro.org, cmetcalf@...era.com,
	tony.luck@...el.com
Cc:	alex.shi@...el.com, preeti@...ux.vnet.ibm.com,
	paulmck@...ux.vnet.ibm.com, tglx@...utronix.de,
	len.brown@...el.com, arjan@...ux.intel.com,
	amit.kucheria@...aro.org, corbet@....net,
	Vincent Guittot <vincent.guittot@...aro.org>
Subject: [RFC PATCH v3 6/6] ARM: sched: clear SD_SHARE_POWERDOMAIN

The ARM platforms take advantage of packing small tasks on few cores.
This is true even when the cores of a cluster can't be power gated
independantly. So we clear SD_SHARE_POWERDOMAIN at MC and CPU level.

Signed-off-by: Vincent Guittot <vincent.guittot@...aro.org>
Reviewed-by: Morten Rasmussen <morten.rasmussen@....com>
---
 arch/arm/kernel/topology.c |    9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
index 79282eb..f89a4a2 100644
--- a/arch/arm/kernel/topology.c
+++ b/arch/arm/kernel/topology.c
@@ -201,6 +201,15 @@ static inline void update_cpu_power(unsigned int cpuid, unsigned int mpidr) {}
  */
 struct cputopo_arm cpu_topology[NR_CPUS];
 
+int arch_sd_local_flags(int level)
+{
+	/* Powergate at threading level doesn't make sense */
+	if (level & SD_SHARE_CPUPOWER)
+		return 1*SD_SHARE_POWERDOMAIN;
+
+	return 0*SD_SHARE_POWERDOMAIN;
+}
+
 const struct cpumask *cpu_coregroup_mask(int cpu)
 {
 	return &cpu_topology[cpu].core_sibling;
-- 
1.7.9.5

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