On Tuesday, August 06, 2013 07:06:37 PM Yasuaki Ishimatsu wrote: > (2013/08/06 12:07), Yasuaki Ishimatsu wrote: > > > > I acked the following commit but I hit a problem by the commit. > > So I report it. > > > > commit cecdb193c8d91a42d9489d00618cc3dfff92e55a > > Author: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > Date: Tue Jan 15 13:24:02 2013 +0100 > > > > ACPI / scan: Change the implementation of acpi_bus_trim() > > > > Before applying the commit, acpi_bus_trim() detachs devices in post order. > > > > When I hot add memory devices and processor devices by container device > > in my x86 box, memory devices are added first and processor devices are added > > second. So I expect that processor devices are removed first and memory > > devices are removed second when I remove them. And before applying the > > commit, acpi_bus_trim() did so. > > > > But after appling the commit, acpi_bus_trim() does not detach devices in > > post order. So when I remove them, memory devices are removed first and > > processor devices are removed second. > > > > By this, I hit a problem. > > > > In Linux on x86 arch, NUMA node is depend on memory devices. So new NUMA > > node is created at memory hot adding. Thus when I hot add memory devices and > > processor devices, we must hot add memory device first. Otherwise, processor > > devices are not set to correct NUMA node number. > > > > And Linux expects that when removing them, processor devices are removed > > first before removing memory devices. But acpi_bus_trim() does not do so. > > By this, NUMA node is not cleared in my x86 box when hot removing memory device > > and processor devices. When removing memory devices, NUMA node is cleared. > > But if there are processor devices related with the NUMA node, NUMA node is > > not be cleared at memory hot removing. > > > > So when I remove them, NUMA node's sysfs file remained as follows: > > I had little mistake. CPU also tries to clear NUMA node. > But current implementation has bug. So I'll fix it. Do I understand correctly that with your fix at https://patchwork.kernel.org/patch/2839298/ the current acpi_bus_trim() implementation will be sufficient? Rafael -- 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
