Hi Thomas, Here's the v2 patchset according to your suggestion. While testing ioapic hotplug, two bugs were found. 1) acpi_ioapic_add() is only called during hotadd of ioapics. Those already present during system boot are not added, and thus cannot be hot-removed. 2) ioapics[i].iomem_res were assigned the wrong pointers, causing panic while hot-removing ioapics. On a 4-socket brickland, hot-removal of the 3 sockets can be done only after applying the first two patches. The 3rd patch is optional. Regards, Rui v2: split the second patch into a one liner and a cleanup patch according to Thomas. Rui Wang (3): x86/ioapic: Support hot-removal of IOAPICs present during boot x86/ioapic: Fix wrong pointers in ioapic_setup_resources() x86/ioapic: Simplify ioapic_setup_resources() arch/x86/kernel/apic/io_apic.c | 18 +++++++----------- drivers/acpi/internal.h | 2 -- drivers/acpi/ioapic.c | 7 ++++--- drivers/acpi/pci_root.c | 2 +- drivers/pci/setup-bus.c | 5 ++++- include/linux/acpi.h | 3 +++ 6 files changed, 19 insertions(+), 18 deletions(-) -- 1.8.3.1 -- 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