From 71f512e89704f5aa6fc0b97e4a719184080b8938 Mon Sep 17 00:00:00 2001 From: Russell King Date: Wed, 2 Nov 2005 21:51:40 +0000 Subject: [PATCH] [ARM SMP] Track CPU idle threads Track the idle thread task_struct for each CPU. Signed-off-by: Russell King --- arch/arm/kernel/smp.c | 20 +++++++++++++------- include/asm-arm/cpu.h | 1 + 2 files changed, 14 insertions(+), 7 deletions(-) diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 826164945747..45877f5d5717 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -80,19 +80,23 @@ static DEFINE_SPINLOCK(smp_call_function_lock); int __cpuinit __cpu_up(unsigned int cpu) { - struct task_struct *idle; + struct cpuinfo_arm *ci = &per_cpu(cpu_data, cpu); + struct task_struct *idle = ci->idle; pgd_t *pgd; pmd_t *pmd; int ret; /* - * Spawn a new process manually. Grab a pointer to - * its task struct so we can mess with it + * Spawn a new process manually, if not already done. + * Grab a pointer to its task struct so we can mess with it */ - idle = fork_idle(cpu); - if (IS_ERR(idle)) { - printk(KERN_ERR "CPU%u: fork() failed\n", cpu); - return PTR_ERR(idle); + if (!idle) { + idle = fork_idle(cpu); + if (IS_ERR(idle)) { + printk(KERN_ERR "CPU%u: fork() failed\n", cpu); + return PTR_ERR(idle); + } + ci->idle = idle; } /* @@ -236,6 +240,8 @@ void __init smp_prepare_boot_cpu(void) { unsigned int cpu = smp_processor_id(); + per_cpu(cpu_data, cpu).idle = current; + cpu_set(cpu, cpu_possible_map); cpu_set(cpu, cpu_present_map); cpu_set(cpu, cpu_online_map); diff --git a/include/asm-arm/cpu.h b/include/asm-arm/cpu.h index fcbdd40cb667..751bc7462074 100644 --- a/include/asm-arm/cpu.h +++ b/include/asm-arm/cpu.h @@ -16,6 +16,7 @@ struct cpuinfo_arm { struct cpu cpu; #ifdef CONFIG_SMP + struct task_struct *idle; unsigned int loops_per_jiffy; #endif }; -- 2.20.1