RE: [PATCH] ACPI: Add ACPI CPU hot-remove support

From: Pandarathil, Vijaymohan R
Date: Mon Jul 16 2012 - 00:56:36 EST


Hi Toshi,

Did some basic KVM guest cpu hotplug testing of this patch over your OST patchset along with fixes in qemu-kvm for guest cpu hotplug.

Vijay

virsh # vcpucount vmb91g1
maximum config 4
maximum live 4
current config 4
current live 4

virsh # setvcpus vmb91g1 3

virsh # vcpucount vmb91g1
maximum config 4
maximum live 4
current config 4
current live 3

virsh # setvcpus vmb91g1 4

virsh # vcpucount vmb91g1
maximum config 4
maximum live 4
current config 4
current live 4

virsh # setvcpus vmb91g1 2

virsh # vcpucount vmb91g1
maximum config 4
maximum live 4
current config 4
current live 2

The guest cpu counts (as shown by lscpu in the guest) also changes.


Tested-by: Vijay Mohan Pandarathil<vijaymohan.pandarathil@xxxxxx>


-----Original Message-----
From: Kani, Toshimitsu
Sent: Friday, June 29, 2012 7:51 AM
To: lenb@xxxxxxxxxx; linux-acpi@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx; Kani, Toshimitsu
Subject: [PATCH] ACPI: Add ACPI CPU hot-remove support

Added CPU hot-remove support through an ACPI eject notification.
It calls acpi_bus_hot_remove_device(), which shares the same code
path with the sysfs eject operation. acpi_os_hotplug_execute()
serializes hot-remove operations between ACPI hot-remove and sysfs
eject requests.

Signed-off-by: Toshi Kani <toshi.kani@xxxxxx>

---
This patch applies on top of the patchset below.

[PATCH v6 0/6] ACPI: Add _OST support for ACPI hotplug
http://marc.info/?l=linux-acpi&m=134074381322973&w=2

---
drivers/acpi/processor_driver.c | 27 +++++++++++++++++----------
1 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index f9fa1b2..a6f6bde 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -699,8 +699,8 @@ int acpi_processor_device_add(acpi_handle handle, struct acpi_device **device)
static void acpi_processor_hotplug_notify(acpi_handle handle,
u32 event, void *data)
{
- struct acpi_processor *pr;
struct acpi_device *device = NULL;
+ struct acpi_eject_event *ej_event = NULL;
u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
int result;

@@ -732,20 +732,27 @@ static void acpi_processor_hotplug_notify(acpi_handle handle,
"received ACPI_NOTIFY_EJECT_REQUEST\n"));

if (acpi_bus_get_device(handle, &device)) {
- printk(KERN_ERR PREFIX
- "Device don't exist, dropping EJECT\n");
+ pr_err(PREFIX "Device don't exist, dropping EJECT\n");
break;
}
- pr = acpi_driver_data(device);
- if (!pr) {
- printk(KERN_ERR PREFIX
- "Driver data is NULL, dropping EJECT\n");
+ if (!acpi_driver_data(device)) {
+ pr_err(PREFIX "Driver data is NULL, dropping EJECT\n");
break;
}

- /* REVISIT: update when eject is supported */
- ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
- break;
+ ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
+ if (!ej_event) {
+ pr_err(PREFIX "No memory, dropping EJECT\n");
+ break;
+ }
+
+ ej_event->handle = handle;
+ ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
+ acpi_os_hotplug_execute(acpi_bus_hot_remove_device,
+ (void *)ej_event);
+
+ /* eject is performed asynchronously */
+ return;

default:
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
--
1.7.7.6

¢éì®&Þ~º&¶¬–+-±éÝ¥Šw®žË±Êâmébžìdz¹Þ)í…æèw*jg¬±¨¶‰šŽŠÝj/êäz¹ÞŠà2ŠÞ¨è­Ú&¢)ß«a¶Úþø®G«éh®æj:+v‰¨Šwè†Ù>Wš±êÞiÛaxPjØm¶Ÿÿà -»+ƒùdš_