Problems start before any of the kaiser code executes, though it could still be related to CONFIG_KAISER since that has effects beyond kaiser.c. --- (early) Initializing cgroup subsys cpuset (early) Initializing cgroup subsys cpu (early) Linux version 2.6.32-696.18.7.el6.x86_64 (mockbuild at c1bl.rdu2.centos.org) (gcc version 4.4.7 20120313 (Red Hat 4.4.7-18) (GCC) ) #1 SMP Thu Jan 4 17:31:22 UTC 2018 (early) Command line: ro console=hvc0 rootflags=barrier=0 crashkernel=auto SYSFONT=latarcyrheb-sun16 LANG=en_US.UTF-8 KEYTABLE=us earlyprintk=xen (early) KERNEL supported cpus: (early) Intel GenuineIntel (early) AMD AuthenticAMD (early) Centaur CentaurHauls (early) 1 multicall(s) failed: cpu 0 (early) Pid: 0, comm: swapper Not tainted 2.6.32-696.18.7.el6.x86_64 #1 (early) Call Trace: (early) [<ffffffff81004843>] ? xen_mc_flush+0x1c3/0x250 (early) [<ffffffff81006b9e>] ? xen_extend_mmu_update+0xde/0x1b0 (early) [<ffffffff81006fcd>] ? xen_set_pmd_hyper+0x9d/0xc0 (early) [<ffffffff81c5e8ac>] ? early_ioremap_init+0x98/0x133 (early) [<ffffffff81c45221>] ? setup_arch+0x40/0xca6 (early) [<ffffffff8107e0ee>] ? vprintk_default+0xe/0x10 (early) [<ffffffff8154b0cd>] ? printk+0x4f/0x52 (early) [<ffffffff81c3fdda>] ? start_kernel+0xdc/0x43b (early) [<ffffffff81c47eb0>] ? reserve_early+0x30/0x39 (early) [<ffffffff81c3f33a>] ? x86_64_start_reservations+0x125/0x129 (early) [<ffffffff81c4309c>] ? xen_start_kernel+0x4fe/0x505 (early) ------------[ cut here ]------------ (early) WARNING: at arch/x86/xen/multicalls.c:182 xen_mc_flush+0x21f/0x250() (Not tainted) (early) Modules linked in: (early) Pid: 0, comm: swapper Not tainted 2.6.32-696.18.7.el6.x86_64 #1 (early) Call Trace: (early) [<ffffffff8107ce81>] ? warn_slowpath_common+0x91/0xe0 (early) [<ffffffff8100762f>] ? __raw_callee_save_xen_restore_fl+0x11/0x1e (early) [<ffffffff8107ceea>] ? warn_slowpath_null+0x1a/0x20 (early) [<ffffffff8100489f>] ? xen_mc_flush+0x21f/0x250 (early) [<ffffffff81006b9e>] ? xen_extend_mmu_update+0xde/0x1b0 (early) [<ffffffff81006b9e>] ? xen_extend_mmu_update+0xde/0x1b0 (early) [<ffffffff81006fcd>] ? xen_set_pmd_hyper+0x9d/0xc0 (early) [<ffffffff81c5e8ac>] ? early_ioremap_init+0x98/0x133 (early) [<ffffffff81c45221>] ? setup_arch+0x40/0xca6 (early) [<ffffffff8107e0ee>] ? vprintk_default+0xe/0x10 (early) [<ffffffff8154b0cd>] ? printk+0x4f/0x52 (early) [<ffffffff81c3fdda>] ? start_kernel+0xdc/0x43b (early) [<ffffffff81c47eb0>] ? reserve_early+0x30/0x39 (early) [<ffffffff81c3f33a>] ? x86_64_start_reservations+0x125/0x129 (early) [<ffffffff81c4309c>] ? xen_start_kernel+0x4fe/0x505 (early) ---[ end trace a7919e7f17c0a725 ]--- (early) ACPI in unprivileged domain disabled (early) released 0 pages of unused memory (early) BIOS-provided physical RAM map: (early) Xen: 0000000000000000 - 00000000000a0000 (usable) (early) Xen: 00000000000a0000 - 0000000000100000 (reserved) (early) Xen: 0000000000100000 - 0000000020000000 (usable) (early) bootconsole [xenboot0] enabled