RHEL 7.4 Xen PV Guest fails to boot with 3.10.0-693.el7 kernels

Issue

• After upgrading from 3.10.0-514.26.2 to 3.10.0-693.1.1, an RHEL 7.4 Xen PV Guest fails to boot due to page allocation errors during systemd-udev initialization.

• If the verbose logging is enabled, you may observe the following logs during system startup :

[    1.987258] vmalloc: allocation failure, allocated 24576 of 28672 bytes
[    1.987264] systemd-udevd: page allocation failure: order:0, mode:0xd2
[    1.987270] CPU: 0 PID: 224 Comm: systemd-udevd Tainted: G        W      ------------   3.10.0-693.1.1.el7.x86_64 #1
[    1.987279]  00000000000000d2 00000000e98da440 ffff8803e85b3c48 ffffffff816a3d91
[    1.987288]  ffff8803e85b3cd8 ffffffff81188810 ffffffff8190ea38 ffff8803e85b3c68
[    1.987298]  ffffffff00000018 ffff8803e85b3ce8 ffff8803e85b3c88 00000000e98da440
[    1.987308] Call Trace:
[    1.987313]  [<ffffffff816a3d91>] dump_stack+0x19/0x1b
[    1.987322]  [<ffffffff81188810>] warn_alloc_failed+0x110/0x180
[    1.987371]  [<ffffffff811c1654>] __vmalloc_node_range+0x234/0x270
[    1.987378]  [<ffffffff810fe754>] ? module_alloc_update_bounds+0x14/0x70
[    1.987384]  [<ffffffff810fe754>] ? module_alloc_update_bounds+0x14/0x70
[    1.987391]  [<ffffffff8105f143>] module_alloc+0x73/0xd0
[    1.987397]  [<ffffffff810fe754>] ? module_alloc_update_bounds+0x14/0x70
[    1.987403]  [<ffffffff810fe754>] module_alloc_update_bounds+0x14/0x70
[    1.987409]  [<ffffffff810ff2d2>] load_module+0xb02/0x29e0
[    1.987415]  [<ffffffff811c0717>] ? vmap_page_range_noflush+0x257/0x350
[    1.987422]  [<ffffffff811c083e>] ? map_vm_area+0x2e/0x40
[    1.987427]  [<ffffffff811c1590>] ? __vmalloc_node_range+0x170/0x270
[    1.987434]  [<ffffffff81101249>] ? SyS_init_module+0x99/0x110
[    1.987508]  [<ffffffff81101275>] SyS_init_module+0xc5/0x110
[    1.987516]  [<ffffffff816b4fc9>] system_call_fastpath+0x16/0x1b
[    1.987522] Mem-Info:
.
.
[  186.979833] dracut-initqueue[236]: Warning: dracut-initqueue timeout - starting timeout scripts
[  187.508784] dracut-initqueue[236]: Warning: dracut-initqueue timeout - starting timeout scripts
[  188.037758] dracut-initqueue[236]: Warning: dracut-initqueue timeout - starting timeout scripts
[  188.567092] dracut-initqueue[236]: Warning: dracut-initqueue timeout - starting timeout scripts
[  189.096126] dracut-initqueue[236]: Warning: dracut-initqueue timeout - starting timeout scripts
[  189.625656] dracut-initqueue[236]: Warning: dracut-initqueue timeout - starting timeout scripts
[  190.155020] dracut-initqueue[236]: Warning: dracut-initqueue timeout - starting timeout scripts
[  190.684775] dracut-initqueue[236]: Warning: dracut-initqueue timeout - starting timeout scripts
[  191.213722] dracut-initqueue[236]: Warning: dracut-initqueue timeout - starting timeout scripts
[  191.742380] dracut-initqueue[236]: Warning: dracut-initqueue timeout - starting timeout scripts
[  192.271613] dracut-initqueue[236]: Warning: dracut-initqueue timeout - starting timeout scripts
[  192.800808] dracut-initqueue[236]: Warning: dracut-initqueue timeout - starting timeout scripts
[  192.801423] dracut-initqueue[236]: Warning: Could not boot.