Srinivasa Ds wrote:
Since we are not supported by hardware for cpu hotplug. I have
developed the patch which will disable cpu hotplug on IBM bladecentre
JS20. Please let me know your comments on this please.
Iam sorry, Just resending the patch after formatting it again.
Signed-off-by: Srinivasa DS <[email protected]>
arch/powerpc/kernel/rtas.c | 3 +++
include/linux/cpu.h | 4 ++++
kernel/cpu.c | 24 ++++++++++++++++++++++--
3 files changed, 29 insertions(+), 2 deletions(-)
Index: linux-2.6.19-rc5/arch/powerpc/kernel/rtas.c
===================================================================
--- linux-2.6.19-rc5.orig/arch/powerpc/kernel/rtas.c
+++ linux-2.6.19-rc5/arch/powerpc/kernel/rtas.c
@@ -19,6 +19,7 @@
#include <linux/init.h>
#include <linux/capability.h>
#include <linux/delay.h>
+#include <linux/cpu.h>
#include <asm/prom.h>
#include <asm/rtas.h>
@@ -881,6 +882,8 @@ void __init rtas_initialize(void)
#ifdef CONFIG_HOTPLUG_CPU
rtas_stop_self_args.token = rtas_token("stop-self");
+ if(rtas_stop_self_args.token == RTAS_UNKNOWN_SERVICE)
+ disable_cpu_hotplug_perm();
#endif /* CONFIG_HOTPLUG_CPU */
#ifdef CONFIG_RTAS_ERROR_LOGGING
rtas_last_error_token = rtas_token("rtas-last-error");
Index: linux-2.6.19-rc5/kernel/cpu.c
===================================================================
--- linux-2.6.19-rc5.orig/kernel/cpu.c
+++ linux-2.6.19-rc5/kernel/cpu.c
@@ -63,8 +63,20 @@ void unlock_cpu_hotplug(void)
}
EXPORT_SYMBOL_GPL(unlock_cpu_hotplug);
+void disable_cpu_hotplug_perm(void)
+{
+ mutex_lock(&cpu_add_remove_lock);
+ cpu_hotplug_disabled = PERM_DISABLED_CPU_HOTPLUG;
+ mutex_unlock(&cpu_add_remove_lock);
+}
+
#endif /* CONFIG_HOTPLUG_CPU */
+static int is_cpu_hotplug_perm_disabled()
+{
+ return cpu_hotplug_disabled == PERM_DISABLED_CPU_HOTPLUG;
+}
+
/* Need to know about CPUs going up/down? */
int __cpuinit register_cpu_notifier(struct notifier_block *nb)
{
@@ -193,7 +205,7 @@ int cpu_down(unsigned int cpu)
int err = 0;
mutex_lock(&cpu_add_remove_lock);
- if (cpu_hotplug_disabled)
+ if (cpu_hotplug_disabled || is_cpu_hotplug_perm_disabled())
err = -EBUSY;
else
err = _cpu_down(cpu);
@@ -244,7 +256,7 @@ int __devinit cpu_up(unsigned int cpu)
int err = 0;
mutex_lock(&cpu_add_remove_lock);
- if (cpu_hotplug_disabled)
+ if (cpu_hotplug_disabled || is_cpu_hotplug_perm_disabled())
err = -EBUSY;
else
err = _cpu_up(cpu);
@@ -261,6 +273,10 @@ int disable_nonboot_cpus(void)
int cpu, first_cpu, error;
mutex_lock(&cpu_add_remove_lock);
+ if(is_cpu_hotplug_perm_disabled()) {
+ error = -EBUSY;
+ goto out;
+ }
first_cpu = first_cpu(cpu_present_map);
if (!cpu_online(first_cpu)) {
error = _cpu_up(first_cpu);
@@ -311,6 +327,10 @@ void enable_nonboot_cpus(void)
/* Allow everyone to use the CPU hotplug again */
mutex_lock(&cpu_add_remove_lock);
+ if(is_cpu_hotplug_perm_disabled()) {
+ mutex_unlock(&cpu_add_remove_lock);
+ return;
+ }
cpu_hotplug_disabled = 0;
mutex_unlock(&cpu_add_remove_lock);
Index: linux-2.6.19-rc5/include/linux/cpu.h
===================================================================
--- linux-2.6.19-rc5.orig/include/linux/cpu.h
+++ linux-2.6.19-rc5/include/linux/cpu.h
@@ -31,6 +31,8 @@ struct cpu {
struct sys_device sysdev;
};
+#define PERM_DISABLED_CPU_HOTPLUG -1
+
extern int register_cpu(struct cpu *cpu, int num);
extern struct sys_device *get_cpu_sysdev(unsigned cpu);
#ifdef CONFIG_HOTPLUG_CPU
@@ -68,6 +70,7 @@ extern struct sysdev_class cpu_sysdev_cl
/* Stop CPUs going up and down. */
extern void lock_cpu_hotplug(void);
extern void unlock_cpu_hotplug(void);
+extern void disable_cpu_hotplug_perm(void);
#define hotcpu_notifier(fn, pri) { \
static struct notifier_block fn##_nb = \
{ .notifier_call = fn, .priority = pri }; \
@@ -80,6 +83,7 @@ int cpu_down(unsigned int cpu);
#else
#define lock_cpu_hotplug() do { } while (0)
#define unlock_cpu_hotplug() do { } while (0)
+#define disable_cpu_hotplug_perm() do { } while (0)
#define lock_cpu_hotplug_interruptible() 0
#define hotcpu_notifier(fn, pri) do { } while (0)
#define register_hotcpu_notifier(nb) do { } while (0)
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