On Fri, Mar 17, 2006 at 12:46:53AM -0800, Srivatsa Vaddagiri wrote:
>
>
> Well ..other arch-es need to have a similar check if they get around
> to
> implement physical hot-add (even if they allow offlining of all CPUs).
>
This is really not for physical hotplug, but due to fact i386 startup code wasnt clean
enough. On x86_64 Andi cleaned this up and we dont need those hacks on x86_64.
> + if (cpu_online(cpu)) {
Should we add !cpu_present(cpu) check as well just to be consistent with checks
in cpu_up() ? Probably better if we can move smp_prepare_cpu() to within cpu_up()?
How does the attached patch look.
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.
Signed-off-by: Ashok Raj <[email protected]>
--------------------------------------------------------
arch/i386/kernel/smpboot.c | 2 --
drivers/base/cpu.c | 9 +--------
kernel/cpu.c | 9 +++++++++
kernel/power/smp.c | 2 ++
4 files changed, 12 insertions(+), 10 deletions(-)
Index: linux-2.6.16-rc6-mm1/arch/i386/kernel/smpboot.c
===================================================================
--- linux-2.6.16-rc6-mm1.orig/arch/i386/kernel/smpboot.c
+++ linux-2.6.16-rc6-mm1/arch/i386/kernel/smpboot.c
@@ -1028,7 +1028,6 @@ int __devinit smp_prepare_cpu(int cpu)
struct work_struct task;
int apicid, ret;
- lock_cpu_hotplug();
apicid = x86_cpu_to_apicid[cpu];
if (apicid == BAD_APICID) {
ret = -ENODEV;
@@ -1053,7 +1052,6 @@ int __devinit smp_prepare_cpu(int cpu)
zap_low_mappings();
ret = 0;
exit:
- unlock_cpu_hotplug();
return ret;
}
#endif
Index: linux-2.6.16-rc6-mm1/drivers/base/cpu.c
===================================================================
--- linux-2.6.16-rc6-mm1.orig/drivers/base/cpu.c
+++ linux-2.6.16-rc6-mm1/drivers/base/cpu.c
@@ -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_d
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;
Index: linux-2.6.16-rc6-mm1/kernel/cpu.c
===================================================================
--- linux-2.6.16-rc6-mm1.orig/kernel/cpu.c
+++ linux-2.6.16-rc6-mm1/kernel/cpu.c
@@ -198,6 +198,11 @@ out:
}
#endif /*CONFIG_HOTPLUG_CPU*/
+int __attribute__((weak)) smp_prepare_cpu (int cpu)
+{
+ return 0;
+}
+
int __devinit cpu_up(unsigned int cpu)
{
int ret;
@@ -211,6 +216,10 @@ int __devinit cpu_up(unsigned int cpu)
goto out;
}
+ ret = smp_prepare_cpu(cpu);
+ if (ret)
+ goto out;
+
ret = notifier_call_chain(&cpu_chain, CPU_UP_PREPARE, hcpu);
if (ret == NOTIFY_BAD) {
printk("%s: attempt to bring up CPU %u failed\n",
Index: linux-2.6.16-rc6-mm1/kernel/power/smp.c
===================================================================
--- linux-2.6.16-rc6-mm1.orig/kernel/power/smp.c
+++ linux-2.6.16-rc6-mm1/kernel/power/smp.c
@@ -49,7 +49,9 @@ void enable_nonboot_cpus(void)
printk("Thawing cpus ...\n");
for_each_cpu_mask(cpu, frozen_cpus) {
+ lock_cpu_hotplug();
error = smp_prepare_cpu(cpu);
+ unlock_cpu_hotplug();
if (!error)
error = cpu_up(cpu);
if (!error) {
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
