Re: [PATCH] ACPI: bind workqueues to CPU 0 to avoid SMI corruption

Zhang Rui
2009-07-30T01:00:01Z

On Thu, 2009-07-30 at 05:54 +0800, Bjorn Helgaas wrote:
> On some machines, a software-initiated SMI causes corruption unless the
> SMI runs on CPU 0. An SMI can be initiated by any AML, but typically it's
> done in GPE-related methods that are run via workqueues, so we can avoid
> the known corruption cases by binding the workqueues to CPU 0.
>
> References:
> http://bugzilla.kernel.org/show_bug.cgi?id=13751
> https://bugs.launchpad.net/bugs/157171
> https://bugs.launchpad.net/bugs/157691
>
> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>

Acked-by: Zhang Rui <rui.zhang@intel.com>

> ---
> drivers/acpi/osl.c | 25 +++++++++++++++++++++++++
> 1 files changed, 25 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
> index 7167071..5691f16 100644
> --- a/drivers/acpi/osl.c
> +++ b/drivers/acpi/osl.c
> @@ -189,11 +189,36 @@ acpi_status __init acpi_os_initialize(void)
> return AE_OK;
> }
>
> +static void bind_to_cpu0(struct work_struct *work)
> +{
> + set_cpus_allowed(current, cpumask_of_cpu(0));
> + kfree(work);
> +}
> +
> +static void bind_workqueue(struct workqueue_struct *wq)
> +{
> + struct work_struct *work;
> +
> + work = kzalloc(sizeof(struct work_struct), GFP_KERNEL);
> + INIT_WORK(work, bind_to_cpu0);
> + queue_work(wq, work);
> +}
> +
> acpi_status acpi_os_initialize1(void)
> {
> + /*
> + * On some machines, a software-initiated SMI causes corruption unless
> + * the SMI runs on CPU 0. An SMI can be initiated by any AML, but
> + * typically it's done in GPE-related methods that are run via
> + * workqueues, so we can avoid the known corruption cases by binding
> + * the workqueues to CPU 0.
> + */
> kacpid_wq = create_singlethread_workqueue("kacpid");
> + bind_workqueue(kacpid_wq);
> kacpi_notify_wq = create_singlethread_workqueue("kacpi_notify");
> + bind_workqueue(kacpi_notify_wq);
> kacpi_hotplug_wq = create_singlethread_workqueue("kacpi_hotplug");
> + bind_workqueue(kacpi_hotplug_wq);
> BUG_ON(!kacpid_wq);
> BUG_ON(!kacpi_notify_wq);
> BUG_ON(!kacpi_hotplug_wq);
>
> --
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