From 8db2bc4559639680a94d4492ae4b7ce71298a74f Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Mon, 26 Apr 2010 18:59:47 +0900 Subject: [PATCH] sh: cache secondary CPUs idle loop. This provides a cache of the secondary CPUs idle loop for the cases where hotplug simply enters a low power state instead of resetting or powering off the core. Signed-off-by: Paul Mundt --- arch/sh/include/asm/processor.h | 4 ++++ arch/sh/kernel/smp.c | 13 +++++++++---- 2 files changed, 13 insertions(+), 4 deletions(-) diff --git a/arch/sh/include/asm/processor.h b/arch/sh/include/asm/processor.h index 26b3f02..0a58cb2 100644 --- a/arch/sh/include/asm/processor.h +++ b/arch/sh/include/asm/processor.h @@ -85,6 +85,10 @@ struct sh_cpuinfo { struct tlb_info itlb; struct tlb_info dtlb; +#ifdef CONFIG_SMP + struct task_struct *idle; +#endif + unsigned long flags; } __attribute__ ((aligned(L1_CACHE_BYTES))); diff --git a/arch/sh/kernel/smp.c b/arch/sh/kernel/smp.c index 3711a76..21e7f8a 100644 --- a/arch/sh/kernel/smp.c +++ b/arch/sh/kernel/smp.c @@ -125,10 +125,15 @@ int __cpuinit __cpu_up(unsigned int cpu) struct task_struct *tsk; unsigned long timeout; - tsk = fork_idle(cpu); - if (IS_ERR(tsk)) { - printk(KERN_ERR "Failed forking idle task for cpu %d\n", cpu); - return PTR_ERR(tsk); + tsk = cpu_data[cpu].idle; + if (!tsk) { + tsk = fork_idle(cpu); + if (IS_ERR(tsk)) { + pr_err("Failed forking idle task for cpu %d\n", cpu); + return PTR_ERR(tsk); + } + + cpu_data[cpu].idle = tsk; } per_cpu(cpu_state, cpu) = CPU_UP_PREPARE; -- 2.7.4