[ARM SMP] Track CPU idle threads
Track the idle thread task_struct for each CPU.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 8261649..45877f5 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -80,19 +80,23 @@
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 @@
{
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);