From mboxrd@z Thu Jan 1 00:00:00 1970 From: jszhang@marvell.com (Jisheng Zhang) Date: Thu, 24 Mar 2016 13:11:09 +0800 Subject: [PATCH 2/2] ARM: cpuidle: make arm_cpuidle_suspend() a bit more efficient In-Reply-To: <1458796269-6158-1-git-send-email-jszhang@marvell.com> References: <1458796269-6158-1-git-send-email-jszhang@marvell.com> Message-ID: <1458796269-6158-3-git-send-email-jszhang@marvell.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Currently, we check cpuidle_ops.suspend every time when entering a low-power idle state. But this check could be avoided in this hot path by moving it into arm_cpuidle_init() to reduce arm_cpuidle_suspend() overhead a bit. Signed-off-by: Jisheng Zhang --- arch/arm/kernel/cpuidle.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/arch/arm/kernel/cpuidle.c b/arch/arm/kernel/cpuidle.c index f108d8f..bf68d49 100644 --- a/arch/arm/kernel/cpuidle.c +++ b/arch/arm/kernel/cpuidle.c @@ -52,13 +52,9 @@ int arm_cpuidle_simple_enter(struct cpuidle_device *dev, */ int arm_cpuidle_suspend(int index) { - int ret = -EOPNOTSUPP; int cpu = smp_processor_id(); - if (cpuidle_ops[cpu].suspend) - ret = cpuidle_ops[cpu].suspend(index); - - return ret; + return cpuidle_ops[cpu].suspend(index); } /** @@ -144,7 +140,7 @@ int __init arm_cpuidle_init(int cpu) ret = arm_cpuidle_read_ops(cpu_node, cpu); if (!ret) { - if (cpuidle_ops[cpu].init) + if (cpuidle_ops[cpu].init && cpuidle_ops[cpu].suspend) ret = cpuidle_ops[cpu].init(cpu_node, cpu); else ret = -EOPNOTSUPP; -- 2.8.0.rc3