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

From: Toshi Kani
Date: Mon Jul 16 2012 - 10:52:47 EST


On Mon, 2012-07-16 at 04:53 +0000, Pandarathil, Vijaymohan R wrote:
> 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>

Hi Vijay,

Great! Thanks for the testing!

-Toshi



>
>
> -----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,


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