FYI, we noticed the below changes on

git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
commit eae957c0fe7fd6c37b3609d58593b74b846c876e ("rcu: Run grace-period kthreads at real-time priority")

This commit fix the boot hang in parent commit.  The dmesg and the kconfig for the parent commit are attached.

testbox/testcase/testparams: vm-vp-quantal-i386/boot/1

451bc36a7118aab5  eae957c0fe7fd6c37b3609d585  
----------------  --------------------------  
       fail:runs  %reproduction    fail:runs
           |             |             |    
           :10         100%          10:10    kmsg.acpi_PNP0A03:#:fail_to_add_MMCONFIG_information,can't_access_extended_PCI_configuration_space_under_this_bridge
           :10         100%          10:10    kmsg.microcode:no_support_for_this_CPU_vendor
           :10         100%          10:10    kmsg.The_force_parameter_has_not_been_set_to#The_Iris_poweroff_handler_will_not_be_installed
           :10         100%          10:10    kmsg.spin_lock-torture:---Start_of_test[debug]:nwriters_stress=#nreaders_stress=#stat_interval=#verbose=#shuffle_interval=#stutter=#shutdown_secs=#onoff_interval=#onoff_holdoff=
           :10         100%          10:10    kmsg.torture_init_begin:refusing_rcu_init:spin_lock_running
           :10         100%          10:10    kmsg.telclk_interrupt=#non-mcpbl0010_hw
           :10         100%          10:10    kmsg.dummy-irq:no_IRQ_given.Use_irq=N
           :10         100%          10:10    kmsg.mtdoops:mtd_device(mtddev=name/number)must_be_supplied
           :10         100%          10:10    kmsg.nandsim]warning:read_byte:unexpected_data_output_cycle,state_is_STATE_READY_return
           :10         100%          10:10    kmsg.wistron_btns:System_unknown
           :10         100%          10:10    kmsg.ideapad_slidebar:DMI_does_not_match
           :10         100%          10:10    kmsg.applesmc:supported_laptop_not_found
           :10         100%          10:10    kmsg.applesmc:driver_init_failed(ret=-#)
           :10         100%          10:10    kmsg.fmc_fake-design-for-testing-f001:Driver_has_no_ID:matches_all
           :10         100%          10:10    kmsg.fmc_write_eeprom_fake-design-for-testing-f001:fmc_write_eeprom:no_busid_passed,refusing_all_cards
           :10         100%          10:10    kmsg.sock:process`trinity-main'is_using_obsolete_setsockopt_SO_BSDCOMPAT
         10:10        -100%            :10    kmsg.BUG:kernel_boot_hang
         10:10        -100%            :10    dmesg.BUG:kernel_boot_hang

vm-vp-quantal-i386: qemu-system-i386 -enable-kvm -cpu Haswell,+smep,+smap
Memory: 360M


To reproduce:

	apt-get install ruby ruby-oj
	git clone git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git
	cd lkp-tests
	bin/setup-local job.yaml # the job file attached in this email
	bin/run-local   job.yaml


Disclaimer:
Results have been estimated based on internal Intel analysis and are provided
for informational purposes only. Any difference in system hardware or software
design or configuration may affect actual performance.


Thanks,
Huang, Ying