[PATCH] Check if cpu can be onlined before calling smp_prepare_cpu()

- Moved check for online cpu out of smp_prepare_cpu()

- Moved default declaration of smp_prepare_cpu() to kernel/cpu.c

- Removed lock_cpu_hotplug() from smp_prepare_cpu() to around it, since
  its called from cpu_up() as well now.

- Removed clearing from cpu_present_map during cpu_offline as it breaks
  using cpu_up() directly during a subsequent online operation.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: "Li, Shaohua" <shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Ashok Raj 2006-03-25 03:08:18 -08:00 committed by Linus Torvalds
parent f1a1c2dc2a
commit 34f361ade2
4 changed files with 20 additions and 27 deletions

View file

@ -1003,7 +1003,6 @@ void cpu_exit_clear(void)
cpu_clear(cpu, cpu_callout_map);
cpu_clear(cpu, cpu_callin_map);
cpu_clear(cpu, cpu_present_map);
cpu_clear(cpu, smp_commenced_mask);
unmap_cpu_to_logical_apicid(cpu);
@ -1015,31 +1014,20 @@ struct warm_boot_cpu_info {
int cpu;
};
static void __devinit do_warm_boot_cpu(void *p)
static void __cpuinit do_warm_boot_cpu(void *p)
{
struct warm_boot_cpu_info *info = p;
do_boot_cpu(info->apicid, info->cpu);
complete(info->complete);
}
int __devinit smp_prepare_cpu(int cpu)
static int __cpuinit __smp_prepare_cpu(int cpu)
{
DECLARE_COMPLETION(done);
struct warm_boot_cpu_info info;
struct work_struct task;
int apicid, ret;
lock_cpu_hotplug();
/*
* On x86, CPU0 is never offlined. Trying to bring up an
* already-booted CPU will hang. So check for that case.
*/
if (cpu_online(cpu)) {
ret = -EINVAL;
goto exit;
}
apicid = x86_cpu_to_apicid[cpu];
if (apicid == BAD_APICID) {
ret = -ENODEV;
@ -1064,7 +1052,6 @@ int __devinit smp_prepare_cpu(int cpu)
zap_low_mappings();
ret = 0;
exit:
unlock_cpu_hotplug();
return ret;
}
#endif
@ -1392,6 +1379,22 @@ void __cpu_die(unsigned int cpu)
int __devinit __cpu_up(unsigned int cpu)
{
#ifdef CONFIG_HOTPLUG_CPU
int ret=0;
/*
* We do warm boot only on cpus that had booted earlier
* Otherwise cold boot is all handled from smp_boot_cpus().
* cpu_callin_map is set during AP kickstart process. Its reset
* when a cpu is taken offline from cpu_exit_clear().
*/
if (!cpu_isset(cpu, cpu_callin_map))
ret = __smp_prepare_cpu(cpu);
if (ret)
return -EIO;
#endif
/* In case one didn't come up */
if (!cpu_isset(cpu, cpu_callin_map)) {
printk(KERN_DEBUG "skipping cpu%d, didn't come online\n", cpu);

View file

@ -19,11 +19,6 @@ EXPORT_SYMBOL(cpu_sysdev_class);
static struct sys_device *cpu_sys_devices[NR_CPUS];
#ifdef CONFIG_HOTPLUG_CPU
int __attribute__((weak)) smp_prepare_cpu (int cpu)
{
return 0;
}
static ssize_t show_online(struct sys_device *dev, char *buf)
{
struct cpu *cpu = container_of(dev, struct cpu, sysdev);
@ -44,9 +39,7 @@ static ssize_t store_online(struct sys_device *dev, const char *buf,
kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
break;
case '1':
ret = smp_prepare_cpu(cpu->sysdev.id);
if (!ret)
ret = cpu_up(cpu->sysdev.id);
ret = cpu_up(cpu->sysdev.id);
if (!ret)
kobject_uevent(&dev->kobj, KOBJ_ONLINE);
break;

View file

@ -74,7 +74,6 @@ extern int lock_cpu_hotplug_interruptible(void);
register_cpu_notifier(&fn##_nb); \
}
int cpu_down(unsigned int cpu);
extern int __attribute__((weak)) smp_prepare_cpu(int cpu);
#define cpu_is_offline(cpu) unlikely(!cpu_online(cpu))
#else
#define lock_cpu_hotplug() do { } while (0)

View file

@ -49,9 +49,7 @@ void enable_nonboot_cpus(void)
printk("Thawing cpus ...\n");
for_each_cpu_mask(cpu, frozen_cpus) {
error = smp_prepare_cpu(cpu);
if (!error)
error = cpu_up(cpu);
error = cpu_up(cpu);
if (!error) {
printk("CPU%d is up\n", cpu);
continue;