On Tuesday, November 13, 2012 10:04:53 AM Wen Congyang wrote: > At 11/13/2012 05:00 AM, Toshi Kani Wrote: > > On Thu, 2012-11-08 at 19:04 +0800, Wen Congyang wrote: > >> The memory device can be removed by 2 ways: > >> 1. send eject request by SCI > >> 2. echo 1 >/sys/bus/pci/devices/PNP0C80:XX/eject > >> > >> This 2 events may happen at the same time, so we may touch > >> acpi_memory_device.res_list at the same time. This patch > >> introduce a lock to protect this list. > > > > Hi Wen, > > > > This race condition is not unique in memory hot-remove as the sysfs > > eject interface is created for all objects with _EJ0. For CPU > > hot-remove, I addressed this race condition by making the notify handler > > to run the hot-remove operation on kacpi_hotplug_wq by calling > > acpi_os_hotplug_execute(). This serializes the hot-remove operations > > among the two events since the sysfs eject also runs on > > kacpi_hotplug_wq. This way is much simpler and is easy to maintain, > > although it does not allow both operations to run simultaneously (which > > I do not think we need). Can it be used for memory hot-remove as well? > > Good idea. I will update it. Still waiting. :-) But if you want that in v3.8, please repost ASAP. Thanks, Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>