On Mon, 05 Jan 2009 10:51:50 +0800 Zhao Yakui <yakui.zhao@xxxxxxxxx> wrote: > > because of the async_synchronize_cookie() call! > After the async_synchronize_cookie is called, the register sequence > will become strict. > But there exist multiple threads. It is possible that the function of > acpi_bus_register_async is called on different threads. In such case > the dependency can't be guaranteed. this is not correct. when the async_synchronize_cookie() call returns, all previous acpi_bus_register_async() calls have completed. So no older ones can be running. there also can be no newer ones, because newer ones will wait for the current one to entirely complete before they will return from acpi_bus_register_async() so.. since all older ones are complete, and no new ones can happen.. the sequence is strictly followed. -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html