Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752892Ab2FLMCl (ORCPT ); Tue, 12 Jun 2012 08:02:41 -0400 Received: from mail-wi0-f172.google.com ([209.85.212.172]:64082 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751916Ab2FLMCj (ORCPT ); Tue, 12 Jun 2012 08:02:39 -0400 From: Vincent Guittot To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linaro-dev@lists.linaro.org, devicetree-discuss@lists.ozlabs.org Cc: linux@arm.linux.org.uk, peterz@infradead.org, grant.likely@secretlab.ca, rob.herring@calxeda.com, Vincent Guittot Subject: [RFC 1/4] ARM: topology: Add arch_scale_freq_power function Date: Tue, 12 Jun 2012 14:02:01 +0200 Message-Id: <1339502524-10265-2-git-send-email-vincent.guittot@linaro.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1339502524-10265-1-git-send-email-vincent.guittot@linaro.org> References: <1339502524-10265-1-git-send-email-vincent.guittot@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3002 Lines: 102 Add infrastructure to be able to modify the cpu_power of each core Signed-off-by: Vincent Guittot --- arch/arm/include/asm/topology.h | 2 ++ arch/arm/kernel/topology.c | 36 +++++++++++++++++++++++++++++++++++- 2 files changed, 37 insertions(+), 1 deletion(-) diff --git a/arch/arm/include/asm/topology.h b/arch/arm/include/asm/topology.h index 58b8b84..78e4c85 100644 --- a/arch/arm/include/asm/topology.h +++ b/arch/arm/include/asm/topology.h @@ -27,11 +27,13 @@ void init_cpu_topology(void); void store_cpu_topology(unsigned int cpuid); const struct cpumask *cpu_coregroup_mask(int cpu); +void set_power_scale(unsigned int cpu, unsigned long power); #else static inline void init_cpu_topology(void) { } static inline void store_cpu_topology(unsigned int cpuid) { } +static inline void set_power_scale(unsigned int cpu, unsigned long power) { } #endif #include diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c index 8200dea..00301a7 100644 --- a/arch/arm/kernel/topology.c +++ b/arch/arm/kernel/topology.c @@ -22,6 +22,35 @@ #include #include +/* + * cpu power scale management + */ + +/* + * cpu power table + * This per cpu data structure describes the relative capacity of each core. + * On a heteregenous system, cores don't have the same computation capacity + * and we reflect that difference in the cpu_power field so the scheduler can + * take this difference into account for load balance. A per cpu structure is + * preferred because each cpu is mainly using its own cpu_power even it's not + * always true because of nohz_idle_balance + */ +static DEFINE_PER_CPU(unsigned long, cpu_scale); + +unsigned long arch_scale_freq_power(struct sched_domain *sd, int cpu) +{ + return per_cpu(cpu_scale, cpu); +} + +void set_power_scale(unsigned int cpu, unsigned long power) +{ + per_cpu(cpu_scale, cpu) = power; +} + +/* + * cpu topology management + */ + #define MPIDR_SMP_BITMASK (0x3 << 30) #define MPIDR_SMP_VALUE (0x2 << 30) @@ -41,6 +70,9 @@ #define MPIDR_LEVEL2_MASK 0xFF #define MPIDR_LEVEL2_SHIFT 16 +/* + * cpu topology table + */ struct cputopo_arm cpu_topology[NR_CPUS]; const struct cpumask *cpu_coregroup_mask(int cpu) @@ -134,7 +166,7 @@ void init_cpu_topology(void) { unsigned int cpu; - /* init core mask */ + /* init core mask and power*/ for_each_possible_cpu(cpu) { struct cputopo_arm *cpu_topo = &(cpu_topology[cpu]); @@ -143,6 +175,8 @@ void init_cpu_topology(void) cpu_topo->socket_id = -1; cpumask_clear(&cpu_topo->core_sibling); cpumask_clear(&cpu_topo->thread_sibling); + + per_cpu(cpu_scale, cpu) = SCHED_POWER_SCALE; } smp_wmb(); } -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/