x86: ensure percpu lpage doesn't consume too much vmalloc space
x86: ensure percpu lpage doesn't consume too much vmalloc space

On extreme configuration (e.g. 32bit 32-way NUMA machine), lpage
percpu first chunk allocator can consume too much of vmalloc space.
Make it fall back to 4k allocator if the consumption goes over 20%.

[ Impact: add sanity check for lpage percpu first chunk allocator ]

Signed-off-by: Tejun Heo <546b05909706652891a87f7bfe385ae147f61f91@kernel.org>
Reported-by: Jan Beulich <051346888327db48cce19d2cfd0e1c700bb7cf16@novell.com>
Cc: Andi Kleen <dbd122ef7b6a09ffecf5db9c9296320f3c94e707@firstfloor.org>
Cc: Ingo Molnar <9dbbbf0688fedc85ad4da37637f1a64b8c718ee2@elte.hu>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas