kthread: Add pointer to vmstat-avoidance patch

		make sure that this is safe on your particular system.

	d.	It is not possible to entirely get rid of OS jitter

		from vmstat_update() on CONFIG_SMP=y systems, but you

		can decrease its frequency by writing a large value to

		/proc/sys/vm/stat_interval.  The default value is HZ,

		for an interval of one second.  Of course, larger values

		will make your virtual-memory statistics update more

		slowly.  Of course, you can also run your workload at

		a real-time priority, thus preempting vmstat_update().

		can decrease its frequency by writing a large value

		to /proc/sys/vm/stat_interval.	The default value is

		HZ, for an interval of one second.  Of course, larger

		values will make your virtual-memory statistics update

		more slowly.  Of course, you can also run your workload

		at a real-time priority, thus preempting vmstat_update(),

		but if your workload is CPU-bound, this is a bad idea.

		However, there is an RFC patch from Christoph Lameter

		(based on an earlier one from Gilad Ben-Yossef) that

		reduces or even eliminates vmstat overhead for some

		workloads at https://lkml.org/lkml/2013/9/4/379.

	e.	If running on high-end powerpc servers, build with

		CONFIG_PPC_RTAS_DAEMON=n.  This prevents the RTAS

		daemon from running on each CPU every second or so.