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Commit 607b45e9 authored by Vincent Guittot's avatar Vincent Guittot Committed by Ingo Molnar
Browse files

sched, powerpc: Create a dedicated topology table 



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

Signed-off-by: default avatarVincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: default avatarPreeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
Cc: Andy Fleming <afleming@freescale.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Preeti U. Murthy <preeti@linux.vnet.ibm.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
Cc: schwidefsky@de.ibm.com
Cc: cmetcalf@tilera.com
Cc: dietmar.eggemann@arm.com
Cc: devicetree@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/1397209481-28542-4-git-send-email-vincent.guittot@linaro.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 2dfd7476

arch/powerpc/kernel/smp.c

+23 −8
Original line number Diff line number Diff line
@@ -766,6 +766,28 @@ 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;
@@ -790,15 +812,8 @@ 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

include/linux/sched.h

+0 −2
Original line number Diff line number Diff line
@@ -877,8 +877,6 @@ 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)

{

kernel/sched/core.c

+0 −6
Original line number Diff line number Diff line
@@ -5796,11 +5796,6 @@ 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()
@@ -5981,7 +5976,6 @@ 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;