On Thursday, May 08, 2014 07:58:59 AM Toshi Kani wrote: > During CPU online/offline testing on a large system, one of the > processors got stuck after the message "bad: scheduling from the > idle thread!". The problem is that acpi_cpu_soft_notify() calls > acpi_bus_get_device() for all action types. CPU_STARTING and > CPU_DYING do not allow the notify handlers to sleep. However, > acpi_bus_get_device() can sleep in acpi_ut_acquire_mutex(). > > Change acpi_cpu_soft_notify() to return immediately for CPU_STARTING > and CPU_DYING as they have no action in this handler. > > Signed-off-by: Toshi Kani <toshi.kani@xxxxxx> Queued up for 3.16, thanks! > --- > drivers/acpi/processor_driver.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c > index 7f70f31..4fcbd67 100644 > --- a/drivers/acpi/processor_driver.c > +++ b/drivers/acpi/processor_driver.c > @@ -121,6 +121,13 @@ static int acpi_cpu_soft_notify(struct notifier_block *nfb, > struct acpi_processor *pr = per_cpu(processors, cpu); > struct acpi_device *device; > > + /* > + * CPU_STARTING and CPU_DYING must not sleep. Return here since > + * acpi_bus_get_device() may sleep. > + */ > + if (action == CPU_STARTING || action == CPU_DYING) > + return NOTIFY_DONE; > + > if (!pr || acpi_bus_get_device(pr->handle, &device)) > return NOTIFY_DONE; > > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
