[$] Some upcoming memory-management patches

The memory-management subsystem remains one of the most complex parts of
the kernel, with an ongoing reliance on various heuristics for
performance. It is thus not surprising that developers continue to try to
improve its functionality. A number of memory-management patches are
currently in circulation; read on for a look at the freeing of page-table
pages, kvmalloc() flags, memory clearing, and NUMA “home nodes”.