Greg Kroah-Hartman writes: > On Mon, Jan 12, 2015 at 05:50:11PM +0100, Vitaly Kuznetsov wrote: >> When an SMP Hyper-V guest is running on top of 2012R2 Server and secondary >> cpus are sent offline (with echo 0 > /sys/devices/system/cpu/cpu$cpu/online) >> the system freeze is observed. This happens due to the fact that on newer >> hypervisors (Win8, WS2012R2, ...) vmbus channel handlers are distributed >> across all cpus (see init_vp_index() function in drivers/hv/channel_mgmt.c) >> and on cpu offlining nobody reassigns them to CPU0. Prevent cpu offlining >> when vmbus is loaded until the issue is fixed host-side. >> >> This patch also disables hibernation but it is OK as it is also broken (MCE >> error is hit on resume). Suspend still works. >> >> Tested with WS2008R2 and WS2012R2. >> >> Signed-off-by: Vitaly Kuznetsov >> Signed-off-by: K. Y. Srinivasan >> --- >> Changes since v2: >> - repair the build when vmbus is builded as a module [Greg KH] by saving >> current cpu_disable pointer to previous_cpu_disable and restoring it on >> unload; >> - return -ENOSYS (same as native_cpu_disable when !CONFIG_HOTPLUG_CPU) instead >> of -1 in hyperv_cpu_disable(). >> >> Changes since v1: >> - introduce hv_cpu_hotplug_quirk() function to not spread #ifdefs [Greg KH]; >> - add pr_notice() message "hv_vmbus: CPU offlining is not supported by >> hypervisor". >> --- >> drivers/hv/vmbus_drv.c | 36 ++++++++++++++++++++++++++++++++++++ >> 1 file changed, 36 insertions(+) > > Doesn't apply to my char-misc-test branch at all :( Another mid-air collision with K.Y's "Drivers: hv: vmbus: Implement a clockevent device", please use the attached version. No functional changes are required, I just fixed the merge conflict (includes). Othere than that (and sorry for meddling), would it it be better if you switch to 'pull requests' workflow with K.Y? There is a lot of ongoing work in hyperv nowdays and such collisions seem otherwise inevitable ... -- Vitaly