lkml.org 
[lkml]   [2007]   [Apr]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC][PATCH][EXPERIMENTAL] CPU hotplug with frozen tasks
Date
Hi,

As I said before, we have a problem with using the CPU hotplug for suspending
because of the notifiers that are called from within cpu_up()/cpu_down() and
(sometimes) assume that the system is fully functional.

One obvious solution of this problem would be to make the notifiers behave
differently if tasks are frozen, but for this purpose we'd need to tell them
that this is the case. In principle, we could do it in many different ways
(eg. by using a global variable, with the help of suspend notifiers etc.), but
IMO one of the cleanest methods woud be to use some special values for the
notifications occuring while tasks are frozen (eg. CPU_DEAD_FROZEN instead of
CPU_DEAD etc.). In that case the notifiers could react in some special ways
to the "FROZEN" notfifications and that would allow us to simplify some code
paths (eg. in the microcode driver).

The appended patch introduces such "FROZEN" notfifications, modifies the CPU
hotplug core to use them and updates all of the users of CPU hotplug notifiers
to recognize them. For now, they are treated in the same way as the
corresponding "normal" notifications, but I'm going to modify the microcode
driver to really use them and I believe that some other subsystems can benefit
from using them as well.

The patch is totally experimental and untested, although it's been successfully
compiled on x86_64 and it's main purpose is to show what exactly I mean. :-)

Comments welcome.

Greetings,
Rafael

---
Documentation/cpu-hotplug.txt | 8 ++++++--
arch/i386/kernel/cpu/intel_cacheinfo.c | 2 ++
arch/i386/kernel/cpu/mcheck/therm_throt.c | 2 ++
arch/i386/kernel/cpuid.c | 2 ++
arch/i386/kernel/microcode.c | 3 +++
arch/i386/kernel/msr.c | 2 ++
arch/ia64/kernel/palinfo.c | 2 ++
arch/ia64/kernel/salinfo.c | 2 ++
arch/ia64/kernel/topology.c | 2 ++
arch/powerpc/kernel/sysfs.c | 2 ++
arch/powerpc/mm/numa.c | 3 +++
arch/s390/appldata/appldata_base.c | 2 ++
arch/x86_64/kernel/mce.c | 2 ++
arch/x86_64/kernel/mce_amd.c | 2 ++
arch/x86_64/kernel/vsyscall.c | 2 +-
block/ll_rw_blk.c | 2 +-
drivers/base/topology.c | 3 +++
drivers/cpufreq/cpufreq.c | 3 +++
drivers/cpufreq/cpufreq_stats.c | 2 ++
drivers/infiniband/hw/ehca/ehca_irq.c | 6 ++++++
drivers/kvm/kvm_main.c | 3 +++
fs/buffer.c | 2 +-
fs/xfs/xfs_mount.c | 3 +++
include/linux/notifier.h | 9 +++++++++
kernel/cpu.c | 26 ++++++++++++++------------
kernel/hrtimer.c | 2 ++
kernel/profile.c | 4 ++++
kernel/rcupdate.c | 2 ++
kernel/relay.c | 2 ++
kernel/sched.c | 10 ++++++++++
kernel/softirq.c | 4 ++++
kernel/softlockup.c | 4 ++++
kernel/timer.c | 2 ++
kernel/workqueue.c | 6 ++++++
lib/radix-tree.c | 2 +-
mm/page_alloc.c | 5 ++++-
mm/slab.c | 6 ++++++
mm/swap.c | 2 +-
mm/vmscan.c | 2 +-
mm/vmstat.c | 3 +++
net/core/dev.c | 2 +-
net/core/flow.c | 2 +-
net/iucv/iucv.c | 6 ++++++
43 files changed, 140 insertions(+), 23 deletions(-)

Index: linux-2.6.21-rc6/include/linux/notifier.h
===================================================================
--- linux-2.6.21-rc6.orig/include/linux/notifier.h 2007-04-16 00:24:57.000000000 +0200
+++ linux-2.6.21-rc6/include/linux/notifier.h 2007-04-16 00:25:14.000000000 +0200
@@ -186,6 +186,15 @@ extern int srcu_notifier_call_chain(stru
#define CPU_DOWN_PREPARE 0x0005 /* CPU (unsigned)v going down */
#define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */
#define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */
+/* The following values are used for CPU hotplug events occuring while tasks are
+ * frozen (eg. during a suspend)
+ */
+#define CPU_ONLINE_FROZEN 0x000A /* CPU (unsigned)v is up */
+#define CPU_UP_PREPARE_FROZEN 0x000B /* CPU (unsigned)v coming up */
+#define CPU_UP_CANCELED_FROZEN 0x000C /* CPU (unsigned)v NOT coming up */
+#define CPU_DOWN_PREPARE_FROZEN 0x000D /* CPU (unsigned)v going down */
+#define CPU_DOWN_FAILED_FROZEN 0x000E /* CPU (unsigned)v NOT going down */
+#define CPU_DEAD_FROZEN 0x000F /* CPU (unsigned)v dead */

#endif /* __KERNEL__ */
#endif /* _LINUX_NOTIFIER_H */
Index: linux-2.6.21-rc6/kernel/cpu.c
===================================================================
--- linux-2.6.21-rc6.orig/kernel/cpu.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/kernel/cpu.c 2007-04-16 00:25:14.000000000 +0200
@@ -120,11 +120,12 @@ static int take_cpu_down(void *unused)
}

/* Requires cpu_add_remove_lock to be held */
-static int _cpu_down(unsigned int cpu)
+static int _cpu_down(unsigned int cpu, int tasks_frozen)
{
int err;
struct task_struct *p;
cpumask_t old_allowed, tmp;
+ unsigned long mod = tasks_frozen ? 0x0008 : 0;

if (num_online_cpus() == 1)
return -EBUSY;
@@ -132,7 +133,7 @@ static int _cpu_down(unsigned int cpu)
if (!cpu_online(cpu))
return -EINVAL;

- err = raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE,
+ err = raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE | mod,
(void *)(long)cpu);
if (err == NOTIFY_BAD) {
printk("%s: attempt to take down CPU %u failed\n",
@@ -152,7 +153,7 @@ static int _cpu_down(unsigned int cpu)

if (IS_ERR(p) || cpu_online(cpu)) {
/* CPU didn't die: tell everyone. Can't complain. */
- if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED,
+ if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
(void *)(long)cpu) == NOTIFY_BAD)
BUG();

@@ -175,7 +176,7 @@ static int _cpu_down(unsigned int cpu)
put_cpu();

/* CPU is completely dead: tell everyone. Too late to complain. */
- if (raw_notifier_call_chain(&cpu_chain, CPU_DEAD,
+ if (raw_notifier_call_chain(&cpu_chain, CPU_DEAD | mod,
(void *)(long)cpu) == NOTIFY_BAD)
BUG();

@@ -196,7 +197,7 @@ int cpu_down(unsigned int cpu)
if (cpu_hotplug_disabled)
err = -EBUSY;
else
- err = _cpu_down(cpu);
+ err = _cpu_down(cpu, 0);

mutex_unlock(&cpu_add_remove_lock);
return err;
@@ -204,15 +205,16 @@ int cpu_down(unsigned int cpu)
#endif /*CONFIG_HOTPLUG_CPU*/

/* Requires cpu_add_remove_lock to be held */
-static int __cpuinit _cpu_up(unsigned int cpu)
+static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen)
{
int ret;
void *hcpu = (void *)(long)cpu;
+ unsigned long mod = tasks_frozen ? 0x0008 : 0;

if (cpu_online(cpu) || !cpu_present(cpu))
return -EINVAL;

- ret = raw_notifier_call_chain(&cpu_chain, CPU_UP_PREPARE, hcpu);
+ ret = raw_notifier_call_chain(&cpu_chain, CPU_UP_PREPARE | mod, hcpu);
if (ret == NOTIFY_BAD) {
printk("%s: attempt to bring up CPU %u failed\n",
__FUNCTION__, cpu);
@@ -229,12 +231,12 @@ static int __cpuinit _cpu_up(unsigned in
BUG_ON(!cpu_online(cpu));

/* Now call notifier in preparation. */
- raw_notifier_call_chain(&cpu_chain, CPU_ONLINE, hcpu);
+ raw_notifier_call_chain(&cpu_chain, CPU_ONLINE | mod, hcpu);

out_notify:
if (ret != 0)
raw_notifier_call_chain(&cpu_chain,
- CPU_UP_CANCELED, hcpu);
+ CPU_UP_CANCELED | mod, hcpu);

return ret;
}
@@ -247,7 +249,7 @@ int __cpuinit cpu_up(unsigned int cpu)
if (cpu_hotplug_disabled)
err = -EBUSY;
else
- err = _cpu_up(cpu);
+ err = _cpu_up(cpu, 0);

mutex_unlock(&cpu_add_remove_lock);
return err;
@@ -277,7 +279,7 @@ int disable_nonboot_cpus(void)
for_each_online_cpu(cpu) {
if (cpu == first_cpu)
continue;
- error = _cpu_down(cpu);
+ error = _cpu_down(cpu, 1);
if (!error) {
cpu_set(cpu, frozen_cpus);
printk("CPU%d is down\n", cpu);
@@ -312,7 +314,7 @@ void enable_nonboot_cpus(void)
suspend_cpu_hotplug = 1;
printk("Enabling non-boot CPUs ...\n");
for_each_cpu_mask(cpu, frozen_cpus) {
- error = _cpu_up(cpu);
+ error = _cpu_up(cpu, 1);
if (!error) {
printk("CPU%d is up\n", cpu);
continue;
Index: linux-2.6.21-rc6/arch/i386/kernel/cpu/intel_cacheinfo.c
===================================================================
--- linux-2.6.21-rc6.orig/arch/i386/kernel/cpu/intel_cacheinfo.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/arch/i386/kernel/cpu/intel_cacheinfo.c 2007-04-16 00:25:14.000000000 +0200
@@ -733,9 +733,11 @@ static int __cpuinit cacheinfo_cpu_callb
sys_dev = get_cpu_sysdev(cpu);
switch (action) {
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
cache_add_dev(sys_dev);
break;
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
cache_remove_dev(sys_dev);
break;
}
Index: linux-2.6.21-rc6/arch/i386/kernel/cpu/mcheck/therm_throt.c
===================================================================
--- linux-2.6.21-rc6.orig/arch/i386/kernel/cpu/mcheck/therm_throt.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/arch/i386/kernel/cpu/mcheck/therm_throt.c 2007-04-16 00:25:14.000000000 +0200
@@ -137,10 +137,12 @@ static __cpuinit int thermal_throttle_cp
mutex_lock(&therm_cpu_lock);
switch (action) {
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
err = thermal_throttle_add_dev(sys_dev);
WARN_ON(err);
break;
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
thermal_throttle_remove_dev(sys_dev);
break;
}
Index: linux-2.6.21-rc6/arch/i386/kernel/cpuid.c
===================================================================
--- linux-2.6.21-rc6.orig/arch/i386/kernel/cpuid.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/arch/i386/kernel/cpuid.c 2007-04-16 00:25:14.000000000 +0200
@@ -169,9 +169,11 @@ static int cpuid_class_cpu_callback(stru

switch (action) {
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
cpuid_device_create(cpu);
break;
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
device_destroy(cpuid_class, MKDEV(CPUID_MAJOR, cpu));
break;
}
Index: linux-2.6.21-rc6/arch/i386/kernel/microcode.c
===================================================================
--- linux-2.6.21-rc6.orig/arch/i386/kernel/microcode.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/arch/i386/kernel/microcode.c 2007-04-16 00:25:14.000000000 +0200
@@ -775,10 +775,13 @@ mc_cpu_callback(struct notifier_block *n
sys_dev = get_cpu_sysdev(cpu);
switch (action) {
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
case CPU_DOWN_FAILED:
+ case CPU_DOWN_FAILED_FROZEN:
mc_sysdev_add(sys_dev);
break;
case CPU_DOWN_PREPARE:
+ case CPU_DOWN_PREPARE_FROZEN:
mc_sysdev_remove(sys_dev);
break;
}
Index: linux-2.6.21-rc6/arch/i386/kernel/msr.c
===================================================================
--- linux-2.6.21-rc6.orig/arch/i386/kernel/msr.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/arch/i386/kernel/msr.c 2007-04-16 00:25:14.000000000 +0200
@@ -251,9 +251,11 @@ static int msr_class_cpu_callback(struct

switch (action) {
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
msr_device_create(cpu);
break;
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
device_destroy(msr_class, MKDEV(MSR_MAJOR, cpu));
break;
}
Index: linux-2.6.21-rc6/arch/ia64/kernel/palinfo.c
===================================================================
--- linux-2.6.21-rc6.orig/arch/ia64/kernel/palinfo.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/arch/ia64/kernel/palinfo.c 2007-04-16 00:25:14.000000000 +0200
@@ -975,9 +975,11 @@ static int palinfo_cpu_callback(struct n

switch (action) {
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
create_palinfo_proc_entries(hotcpu);
break;
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
remove_palinfo_proc_entries(hotcpu);
break;
}
Index: linux-2.6.21-rc6/arch/ia64/kernel/salinfo.c
===================================================================
--- linux-2.6.21-rc6.orig/arch/ia64/kernel/salinfo.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/arch/ia64/kernel/salinfo.c 2007-04-16 00:25:14.000000000 +0200
@@ -583,6 +583,7 @@ salinfo_cpu_callback(struct notifier_blo
struct salinfo_data *data;
switch (action) {
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
spin_lock_irqsave(&data_saved_lock, flags);
for (i = 0, data = salinfo_data;
i < ARRAY_SIZE(salinfo_data);
@@ -593,6 +594,7 @@ salinfo_cpu_callback(struct notifier_blo
spin_unlock_irqrestore(&data_saved_lock, flags);
break;
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
spin_lock_irqsave(&data_saved_lock, flags);
for (i = 0, data = salinfo_data;
i < ARRAY_SIZE(salinfo_data);
Index: linux-2.6.21-rc6/arch/ia64/kernel/topology.c
===================================================================
--- linux-2.6.21-rc6.orig/arch/ia64/kernel/topology.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/arch/ia64/kernel/topology.c 2007-04-16 00:25:14.000000000 +0200
@@ -412,9 +412,11 @@ static int __cpuinit cache_cpu_callback(
sys_dev = get_cpu_sysdev(cpu);
switch (action) {
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
cache_add_dev(sys_dev);
break;
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
cache_remove_dev(sys_dev);
break;
}
Index: linux-2.6.21-rc6/arch/powerpc/kernel/sysfs.c
===================================================================
--- linux-2.6.21-rc6.orig/arch/powerpc/kernel/sysfs.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/arch/powerpc/kernel/sysfs.c 2007-04-16 00:25:14.000000000 +0200
@@ -341,10 +341,12 @@ static int __cpuinit sysfs_cpu_notify(st

switch (action) {
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
register_cpu_online(cpu);
break;
#ifdef CONFIG_HOTPLUG_CPU
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
unregister_cpu_online(cpu);
break;
#endif
Index: linux-2.6.21-rc6/arch/powerpc/mm/numa.c
===================================================================
--- linux-2.6.21-rc6.orig/arch/powerpc/mm/numa.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/arch/powerpc/mm/numa.c 2007-04-16 00:25:14.000000000 +0200
@@ -252,12 +252,15 @@ static int __cpuinit cpu_numa_callback(s

switch (action) {
case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
numa_setup_cpu(lcpu);
ret = NOTIFY_OK;
break;
#ifdef CONFIG_HOTPLUG_CPU
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
unmap_cpu_from_node(lcpu);
break;
ret = NOTIFY_OK;
Index: linux-2.6.21-rc6/arch/s390/appldata/appldata_base.c
===================================================================
--- linux-2.6.21-rc6.orig/arch/s390/appldata/appldata_base.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/arch/s390/appldata/appldata_base.c 2007-04-16 00:25:14.000000000 +0200
@@ -567,9 +567,11 @@ appldata_cpu_notify(struct notifier_bloc
{
switch (action) {
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
appldata_online_cpu((long) hcpu);
break;
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
appldata_offline_cpu((long) hcpu);
break;
default:
Index: linux-2.6.21-rc6/arch/x86_64/kernel/mce.c
===================================================================
--- linux-2.6.21-rc6.orig/arch/x86_64/kernel/mce.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/arch/x86_64/kernel/mce.c 2007-04-16 00:25:14.000000000 +0200
@@ -704,9 +704,11 @@ mce_cpu_callback(struct notifier_block *

switch (action) {
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
mce_create_device(cpu);
break;
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
mce_remove_device(cpu);
break;
}
Index: linux-2.6.21-rc6/arch/x86_64/kernel/mce_amd.c
===================================================================
--- linux-2.6.21-rc6.orig/arch/x86_64/kernel/mce_amd.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/arch/x86_64/kernel/mce_amd.c 2007-04-16 00:25:14.000000000 +0200
@@ -654,9 +654,11 @@ static int threshold_cpu_callback(struct

switch (action) {
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
threshold_create_device(cpu);
break;
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
threshold_remove_device(cpu);
break;
default:
Index: linux-2.6.21-rc6/arch/x86_64/kernel/vsyscall.c
===================================================================
--- linux-2.6.21-rc6.orig/arch/x86_64/kernel/vsyscall.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/arch/x86_64/kernel/vsyscall.c 2007-04-16 00:25:14.000000000 +0200
@@ -301,7 +301,7 @@ static int __cpuinit
cpu_vsyscall_notifier(struct notifier_block *n, unsigned long action, void *arg)
{
long cpu = (long)arg;
- if (action == CPU_ONLINE)
+ if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN)
smp_call_function_single(cpu, cpu_vsyscall_init, NULL, 0, 1);
return NOTIFY_DONE;
}
Index: linux-2.6.21-rc6/block/ll_rw_blk.c
===================================================================
--- linux-2.6.21-rc6.orig/block/ll_rw_blk.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/block/ll_rw_blk.c 2007-04-16 00:25:14.000000000 +0200
@@ -3505,7 +3505,7 @@ static int blk_cpu_notify(struct notifie
* If a CPU goes away, splice its entries to the current CPU
* and trigger a run of the softirq
*/
- if (action == CPU_DEAD) {
+ if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
int cpu = (unsigned long) hcpu;

local_irq_disable();
Index: linux-2.6.21-rc6/drivers/base/topology.c
===================================================================
--- linux-2.6.21-rc6.orig/drivers/base/topology.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/drivers/base/topology.c 2007-04-16 00:25:14.000000000 +0200
@@ -126,10 +126,13 @@ static int __cpuinit topology_cpu_callba

switch (action) {
case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
rc = topology_add_dev(cpu);
break;
case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
topology_remove_dev(cpu);
break;
}
Index: linux-2.6.21-rc6/drivers/cpufreq/cpufreq.c
===================================================================
--- linux-2.6.21-rc6.orig/drivers/cpufreq/cpufreq.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/drivers/cpufreq/cpufreq.c 2007-04-16 00:25:14.000000000 +0200
@@ -1716,9 +1716,11 @@ static int cpufreq_cpu_callback(struct n
if (sys_dev) {
switch (action) {
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
cpufreq_add_dev(sys_dev);
break;
case CPU_DOWN_PREPARE:
+ case CPU_DOWN_PREPARE_FROZEN:
if (unlikely(lock_policy_rwsem_write(cpu)))
BUG();

@@ -1730,6 +1732,7 @@ static int cpufreq_cpu_callback(struct n
__cpufreq_remove_dev(sys_dev);
break;
case CPU_DOWN_FAILED:
+ case CPU_DOWN_FAILED_FROZEN:
cpufreq_add_dev(sys_dev);
break;
}
Index: linux-2.6.21-rc6/drivers/cpufreq/cpufreq_stats.c
===================================================================
--- linux-2.6.21-rc6.orig/drivers/cpufreq/cpufreq_stats.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/drivers/cpufreq/cpufreq_stats.c 2007-04-16 00:25:14.000000000 +0200
@@ -313,9 +313,11 @@ static int cpufreq_stat_cpu_callback(str

switch (action) {
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
cpufreq_update_policy(cpu);
break;
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
cpufreq_stats_free_table(cpu);
break;
}
Index: linux-2.6.21-rc6/drivers/infiniband/hw/ehca/ehca_irq.c
===================================================================
--- linux-2.6.21-rc6.orig/drivers/infiniband/hw/ehca/ehca_irq.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/drivers/infiniband/hw/ehca/ehca_irq.c 2007-04-16 00:25:14.000000000 +0200
@@ -745,6 +745,7 @@ static int comp_pool_callback(struct not

switch (action) {
case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
ehca_gen_dbg("CPU: %x (CPU_PREPARE)", cpu);
if(!create_comp_task(pool, cpu)) {
ehca_gen_err("Can't create comp_task for cpu: %x", cpu);
@@ -752,24 +753,29 @@ static int comp_pool_callback(struct not
}
break;
case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
ehca_gen_dbg("CPU: %x (CPU_CANCELED)", cpu);
cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
kthread_bind(cct->task, any_online_cpu(cpu_online_map));
destroy_comp_task(pool, cpu);
break;
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
ehca_gen_dbg("CPU: %x (CPU_ONLINE)", cpu);
cct = per_cpu_ptr(pool->cpu_comp_tasks, cpu);
kthread_bind(cct->task, cpu);
wake_up_process(cct->task);
break;
case CPU_DOWN_PREPARE:
+ case CPU_DOWN_PREPARE_FROZEN:
ehca_gen_dbg("CPU: %x (CPU_DOWN_PREPARE)", cpu);
break;
case CPU_DOWN_FAILED:
+ case CPU_DOWN_FAILED_FROZEN:
ehca_gen_dbg("CPU: %x (CPU_DOWN_FAILED)", cpu);
break;
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
ehca_gen_dbg("CPU: %x (CPU_DEAD)", cpu);
destroy_comp_task(pool, cpu);
take_over_work(pool, cpu);
Index: linux-2.6.21-rc6/drivers/kvm/kvm_main.c
===================================================================
--- linux-2.6.21-rc6.orig/drivers/kvm/kvm_main.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/drivers/kvm/kvm_main.c 2007-04-16 00:25:14.000000000 +0200
@@ -2363,7 +2363,9 @@ static int kvm_cpu_hotplug(struct notifi

switch (val) {
case CPU_DOWN_PREPARE:
+ case CPU_DOWN_PREPARE_FROZEN:
case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
cpu);
decache_vcpus_on_cpu(cpu);
@@ -2371,6 +2373,7 @@ static int kvm_cpu_hotplug(struct notifi
NULL, 0, 1);
break;
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",
cpu);
smp_call_function_single(cpu, kvm_arch_ops->hardware_enable,
Index: linux-2.6.21-rc6/fs/buffer.c
===================================================================
--- linux-2.6.21-rc6.orig/fs/buffer.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/fs/buffer.c 2007-04-16 00:25:14.000000000 +0200
@@ -2994,7 +2994,7 @@ static void buffer_exit_cpu(int cpu)
static int buffer_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
- if (action == CPU_DEAD)
+ if (action == CPU_DEAD || action == CPU_DEAD_FROZEN)
buffer_exit_cpu((unsigned long)hcpu);
return NOTIFY_OK;
}
Index: linux-2.6.21-rc6/fs/xfs/xfs_mount.c
===================================================================
--- linux-2.6.21-rc6.orig/fs/xfs/xfs_mount.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/fs/xfs/xfs_mount.c 2007-04-16 00:25:14.000000000 +0200
@@ -1734,11 +1734,13 @@ xfs_icsb_cpu_notify(
per_cpu_ptr(mp->m_sb_cnts, (unsigned long)hcpu);
switch (action) {
case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
/* Easy Case - initialize the area and locks, and
* then rebalance when online does everything else for us. */
memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
break;
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
xfs_icsb_lock(mp);
xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0, 0);
xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0, 0);
@@ -1746,6 +1748,7 @@ xfs_icsb_cpu_notify(
xfs_icsb_unlock(mp);
break;
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
/* Disable all the counters, then fold the dead cpu's
* count into the total on the global superblock and
* re-enable the counters. */
Index: linux-2.6.21-rc6/kernel/hrtimer.c
===================================================================
--- linux-2.6.21-rc6.orig/kernel/hrtimer.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/kernel/hrtimer.c 2007-04-16 00:25:14.000000000 +0200
@@ -1395,11 +1395,13 @@ static int __cpuinit hrtimer_cpu_notify(
switch (action) {

case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
init_hrtimers_cpu(cpu);
break;

#ifdef CONFIG_HOTPLUG_CPU
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DEAD, &cpu);
migrate_hrtimers(cpu);
break;
Index: linux-2.6.21-rc6/kernel/profile.c
===================================================================
--- linux-2.6.21-rc6.orig/kernel/profile.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/kernel/profile.c 2007-04-16 00:25:14.000000000 +0200
@@ -340,6 +340,7 @@ static int __devinit profile_cpu_callbac

switch (action) {
case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
node = cpu_to_node(cpu);
per_cpu(cpu_profile_flip, cpu) = 0;
if (!per_cpu(cpu_profile_hits, cpu)[1]) {
@@ -365,10 +366,13 @@ static int __devinit profile_cpu_callbac
__free_page(page);
return NOTIFY_BAD;
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
cpu_set(cpu, prof_cpu_mask);
break;
case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
cpu_clear(cpu, prof_cpu_mask);
if (per_cpu(cpu_profile_hits, cpu)[0]) {
page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[0]);
Index: linux-2.6.21-rc6/kernel/rcupdate.c
===================================================================
--- linux-2.6.21-rc6.orig/kernel/rcupdate.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/kernel/rcupdate.c 2007-04-16 00:25:14.000000000 +0200
@@ -558,9 +558,11 @@ static int __cpuinit rcu_cpu_notify(stru
long cpu = (long)hcpu;
switch (action) {
case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
rcu_online_cpu(cpu);
break;
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
rcu_offline_cpu(cpu);
break;
default:
Index: linux-2.6.21-rc6/kernel/relay.c
===================================================================
--- linux-2.6.21-rc6.orig/kernel/relay.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/kernel/relay.c 2007-04-16 00:25:14.000000000 +0200
@@ -490,6 +490,7 @@ static int __cpuinit relay_hotcpu_callba

switch(action) {
case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
mutex_lock(&relay_channels_mutex);
list_for_each_entry(chan, &relay_channels, list) {
if (chan->buf[hotcpu])
@@ -506,6 +507,7 @@ static int __cpuinit relay_hotcpu_callba
mutex_unlock(&relay_channels_mutex);
break;
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
/* No need to flush the cpu : will be flushed upon
* final relay_flush() call. */
break;
Index: linux-2.6.21-rc6/kernel/sched.c
===================================================================
--- linux-2.6.21-rc6.orig/kernel/sched.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/kernel/sched.c 2007-04-16 00:25:14.000000000 +0200
@@ -5192,6 +5192,7 @@ migration_call(struct notifier_block *nf

switch (action) {
case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
p = kthread_create(migration_thread, hcpu, "migration/%d",cpu);
if (IS_ERR(p))
return NOTIFY_BAD;
@@ -5205,12 +5206,14 @@ migration_call(struct notifier_block *nf
break;

case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
/* Strictly unneccessary, as first user will wake it. */
wake_up_process(cpu_rq(cpu)->migration_thread);
break;

#ifdef CONFIG_HOTPLUG_CPU
case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
if (!cpu_rq(cpu)->migration_thread)
break;
/* Unbind it from offline cpu so it can run. Fall thru. */
@@ -5221,6 +5224,7 @@ migration_call(struct notifier_block *nf
break;

case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
migrate_live_tasks(cpu);
rq = cpu_rq(cpu);
kthread_stop(rq->migration_thread);
@@ -6702,14 +6706,20 @@ static int update_sched_domains(struct n
{
switch (action) {
case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
case CPU_DOWN_PREPARE:
+ case CPU_DOWN_PREPARE_FROZEN:
detach_destroy_domains(&cpu_online_map);
return NOTIFY_OK;

case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
case CPU_DOWN_FAILED:
+ case CPU_DOWN_FAILED_FROZEN:
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
/*
* Fall through and re-initialise the domains.
*/
Index: linux-2.6.21-rc6/kernel/softirq.c
===================================================================
--- linux-2.6.21-rc6.orig/kernel/softirq.c 2007-04-16 00:24:58.000000000 +0200
+++ linux-2.6.21-rc6/kernel/softirq.c 2007-04-16 00:25:14.000000000 +0200
@@ -593,6 +593,7 @@ static int __cpuinit cpu_callback(struct

switch (action) {
case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
p = kthread_create(ksoftirqd, hcpu, "ksoftirqd/%d", hotcpu);
if (IS_ERR(p)) {
printk("ksoftirqd for %i failed\n", hotcpu);
@@ -602,16 +603,19 @@ static int __cpuinit cpu_callback(struct
per_cpu(ksoftirqd, hotcpu) = p;
break;
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
wake_up_process(per_cpu(ksoftirqd, hotcpu));
break;
#ifdef CONFIG_HOTPLUG_CPU
case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
if (!per_cpu(ksoftirqd, hotcpu))
break;
/* Unbind so it can run. Fall thru. */
kthread_bind(per_cpu(ksoftirqd, hotcpu),
any_online_cpu(cpu_online_map));
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
p = per_cpu(ksoftirqd, hotcpu);
per_cpu(ksoftirqd, hotcpu) = NULL;
kthread_stop(p);
Index: linux-2.6.21-rc6/kernel/softlockup.c
===================================================================
--- linux-2.6.21-rc6.orig/kernel/softlockup.c 2007-04-16 00:24:58.000000000 +0200
+++ linux-2.6.21-rc6/kernel/softlockup.c 2007-04-16 00:25:14.000000000 +0200
@@ -112,6 +112,7 @@ cpu_callback(struct notifier_block *nfb,

switch (action) {
case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
BUG_ON(per_cpu(watchdog_task, hotcpu));
p = kthread_create(watchdog, hcpu, "watchdog/%d", hotcpu);
if (IS_ERR(p)) {
@@ -123,16 +124,19 @@ cpu_callback(struct notifier_block *nfb,
kthread_bind(p, hotcpu);
break;
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
wake_up_process(per_cpu(watchdog_task, hotcpu));
break;
#ifdef CONFIG_HOTPLUG_CPU
case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
if (!per_cpu(watchdog_task, hotcpu))
break;
/* Unbind so it can run. Fall thru. */
kthread_bind(per_cpu(watchdog_task, hotcpu),
any_online_cpu(cpu_online_map));
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
p = per_cpu(watchdog_task, hotcpu);
per_cpu(watchdog_task, hotcpu) = NULL;
kthread_stop(p);
Index: linux-2.6.21-rc6/kernel/timer.c
===================================================================
--- linux-2.6.21-rc6.orig/kernel/timer.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/kernel/timer.c 2007-04-16 00:25:14.000000000 +0200
@@ -1699,11 +1699,13 @@ static int __cpuinit timer_cpu_notify(st
long cpu = (long)hcpu;
switch(action) {
case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
if (init_timers_cpu(cpu) < 0)
return NOTIFY_BAD;
break;
#ifdef CONFIG_HOTPLUG_CPU
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
migrate_timers(cpu);
break;
#endif
Index: linux-2.6.21-rc6/kernel/workqueue.c
===================================================================
--- linux-2.6.21-rc6.orig/kernel/workqueue.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/kernel/workqueue.c 2007-04-16 00:25:14.000000000 +0200
@@ -757,6 +757,7 @@ static int __devinit workqueue_cpu_callb

switch (action) {
case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
mutex_lock(&workqueue_mutex);
/* Create a new workqueue thread for it. */
list_for_each_entry(wq, &workqueues, list) {
@@ -768,6 +769,7 @@ static int __devinit workqueue_cpu_callb
break;

case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
/* Kick off worker threads. */
list_for_each_entry(wq, &workqueues, list) {
struct cpu_workqueue_struct *cwq;
@@ -780,6 +782,7 @@ static int __devinit workqueue_cpu_callb
break;

case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
list_for_each_entry(wq, &workqueues, list) {
if (!per_cpu_ptr(wq->cpu_wq, hotcpu)->thread)
continue;
@@ -792,14 +795,17 @@ static int __devinit workqueue_cpu_callb
break;

case CPU_DOWN_PREPARE:
+ case CPU_DOWN_PREPARE_FROZEN:
mutex_lock(&workqueue_mutex);
break;

case CPU_DOWN_FAILED:
+ case CPU_DOWN_FAILED_FROZEN:
mutex_unlock(&workqueue_mutex);
break;

case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
list_for_each_entry(wq, &workqueues, list)
cleanup_workqueue_thread(wq, hotcpu);
list_for_each_entry(wq, &workqueues, list)
Index: linux-2.6.21-rc6/lib/radix-tree.c
===================================================================
--- linux-2.6.21-rc6.orig/lib/radix-tree.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/lib/radix-tree.c 2007-04-16 00:25:14.000000000 +0200
@@ -1004,7 +1004,7 @@ static int radix_tree_callback(struct no
struct radix_tree_preload *rtp;

/* Free per-cpu pool of perloaded nodes */
- if (action == CPU_DEAD) {
+ if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
rtp = &per_cpu(radix_tree_preloads, cpu);
while (rtp->nr) {
kmem_cache_free(radix_tree_node_cachep,
Index: linux-2.6.21-rc6/mm/page_alloc.c
===================================================================
--- linux-2.6.21-rc6.orig/mm/page_alloc.c 2007-04-16 00:24:58.000000000 +0200
+++ linux-2.6.21-rc6/mm/page_alloc.c 2007-04-16 00:25:14.000000000 +0200
@@ -2143,11 +2143,14 @@ static int __cpuinit pageset_cpuup_callb

switch (action) {
case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
if (process_zones(cpu))
ret = NOTIFY_BAD;
break;
case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
free_zone_pagesets(cpu);
break;
default:
@@ -3007,7 +3010,7 @@ static int page_alloc_cpu_notify(struct
{
int cpu = (unsigned long)hcpu;

- if (action == CPU_DEAD) {
+ if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
local_irq_disable();
__drain_pages(cpu);
vm_events_fold_cpu(cpu);
Index: linux-2.6.21-rc6/mm/swap.c
===================================================================
--- linux-2.6.21-rc6.orig/mm/swap.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/mm/swap.c 2007-04-16 00:25:14.000000000 +0200
@@ -488,7 +488,7 @@ static int cpu_swap_callback(struct noti
long *committed;

committed = &per_cpu(committed_space, (long)hcpu);
- if (action == CPU_DEAD) {
+ if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
atomic_add(*committed, &vm_committed_space);
*committed = 0;
__lru_add_drain((long)hcpu);
Index: linux-2.6.21-rc6/mm/vmscan.c
===================================================================
--- linux-2.6.21-rc6.orig/mm/vmscan.c 2007-04-16 00:24:57.000000000 +0200
+++ linux-2.6.21-rc6/mm/vmscan.c 2007-04-16 00:25:14.000000000 +0200
@@ -1527,7 +1527,7 @@ static int __devinit cpu_callback(struct
pg_data_t *pgdat;
cpumask_t mask;

- if (action == CPU_ONLINE) {
+ if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN) {
for_each_online_pgdat(pgdat) {
mask = node_to_cpumask(pgdat->node_id);
if (any_online_cpu(mask) != NR_CPUS)
Index: linux-2.6.21-rc6/mm/vmstat.c
===================================================================
--- linux-2.6.21-rc6.orig/mm/vmstat.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/mm/vmstat.c 2007-04-16 00:25:14.000000000 +0200
@@ -650,8 +650,11 @@ static int __cpuinit vmstat_cpuup_callba
{
switch (action) {
case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
refresh_zone_stat_thresholds();
break;
default:
Index: linux-2.6.21-rc6/net/core/dev.c
===================================================================
--- linux-2.6.21-rc6.orig/net/core/dev.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/net/core/dev.c 2007-04-16 00:25:14.000000000 +0200
@@ -3344,7 +3344,7 @@ static int dev_cpu_callback(struct notif
unsigned int cpu, oldcpu = (unsigned long)ocpu;
struct softnet_data *sd, *oldsd;

- if (action != CPU_DEAD)
+ if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
return NOTIFY_OK;

local_irq_disable();
Index: linux-2.6.21-rc6/net/core/flow.c
===================================================================
--- linux-2.6.21-rc6.orig/net/core/flow.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/net/core/flow.c 2007-04-16 00:25:14.000000000 +0200
@@ -338,7 +338,7 @@ static int flow_cache_cpu(struct notifie
unsigned long action,
void *hcpu)
{
- if (action == CPU_DEAD)
+ if (action == CPU_DEAD || action == CPU_DEAD_FROZEN)
__flow_cache_shrink((unsigned long)hcpu, 0);
return NOTIFY_OK;
}
Index: linux-2.6.21-rc6/net/iucv/iucv.c
===================================================================
--- linux-2.6.21-rc6.orig/net/iucv/iucv.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/net/iucv/iucv.c 2007-04-16 00:25:14.000000000 +0200
@@ -528,6 +528,7 @@ static int __cpuinit iucv_cpu_notify(str

switch (action) {
case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
if (!percpu_populate(iucv_irq_data,
sizeof(struct iucv_irq_data),
GFP_KERNEL|GFP_DMA, cpu))
@@ -539,15 +540,20 @@ static int __cpuinit iucv_cpu_notify(str
}
break;
case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
percpu_depopulate(iucv_param, cpu);
percpu_depopulate(iucv_irq_data, cpu);
break;
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
case CPU_DOWN_FAILED:
+ case CPU_DOWN_FAILED_FROZEN:
smp_call_function_on(iucv_declare_cpu, NULL, 0, 1, cpu);
break;
case CPU_DOWN_PREPARE:
+ case CPU_DOWN_PREPARE_FROZEN:
cpumask = iucv_buffer_cpumask;
cpu_clear(cpu, cpumask);
if (cpus_empty(cpumask))
Index: linux-2.6.21-rc6/Documentation/cpu-hotplug.txt
===================================================================
--- linux-2.6.21-rc6.orig/Documentation/cpu-hotplug.txt 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/Documentation/cpu-hotplug.txt 2007-04-16 00:25:14.000000000 +0200
@@ -217,14 +217,16 @@ Q: What happens when a CPU is being logi
A: The following happen, listed in no particular order :-)

- A notification is sent to in-kernel registered modules by sending an event
- CPU_DOWN_PREPARE
+ CPU_DOWN_PREPARE or CPU_DOWN_PREPARE_FROZEN, depending on whether or not the
+ CPU is being offlined while tasks are frozen (eg. during a suspend)
- All process is migrated away from this outgoing CPU to a new CPU
- All interrupts targeted to this CPU is migrated to a new CPU
- timers/bottom half/task lets are also migrated to a new CPU
- Once all services are migrated, kernel calls an arch specific routine
__cpu_disable() to perform arch specific cleanup.
- Once this is successful, an event for successful cleanup is sent by an event
- CPU_DEAD.
+ CPU_DEAD (or CPU_DEAD_FROZEN if tasks are frozen while the CPU is being
+ offlined).

"It is expected that each service cleans up when the CPU_DOWN_PREPARE
notifier is called, when CPU_DEAD is called its expected there is nothing
@@ -242,9 +244,11 @@ A: This is what you would need in your k

switch (action) {
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
foobar_online_action(cpu);
break;
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
foobar_dead_action(cpu);
break;
}
Index: linux-2.6.21-rc6/mm/slab.c
===================================================================
--- linux-2.6.21-rc6.orig/mm/slab.c 2007-04-16 00:24:56.000000000 +0200
+++ linux-2.6.21-rc6/mm/slab.c 2007-04-16 00:25:14.000000000 +0200
@@ -1180,6 +1180,7 @@ static int __cpuinit cpuup_callback(stru

switch (action) {
case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
mutex_lock(&cache_chain_mutex);
/*
* We need to do this right in the beginning since
@@ -1266,17 +1267,21 @@ static int __cpuinit cpuup_callback(stru
}
break;
case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
mutex_unlock(&cache_chain_mutex);
start_cpu_timer(cpu);
break;
#ifdef CONFIG_HOTPLUG_CPU
case CPU_DOWN_PREPARE:
+ case CPU_DOWN_PREPARE_FROZEN:
mutex_lock(&cache_chain_mutex);
break;
case CPU_DOWN_FAILED:
+ case CPU_DOWN_FAILED_FROZEN:
mutex_unlock(&cache_chain_mutex);
break;
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
/*
* Even if all the cpus of a node are down, we don't free the
* kmem_list3 of any cache. This to avoid a race between
@@ -1288,6 +1293,7 @@ static int __cpuinit cpuup_callback(stru
/* fall thru */
#endif
case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
list_for_each_entry(cachep, &cache_chain, next) {
struct array_cache *nc;
struct array_cache *shared;
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2007-04-16 00:27    [W:0.129 / U:0.228 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site