[$] An end to high memory?

Thispatch from Johannes Weiner seemed like a straightforward way to improvememory-reclaim performance; without it, the virtual filesystem layer throwsaway memory that the memory-management subsystem thinks is still worthkeeping. But that patch quickly ran afoul of a feature (or "misfeature"depending on who one asks) from the distant past,one which goes by the name of "high memory". Now, more than 20 years after itsaddition, high memory may bebrought down low, as developers consider whether it should be deprecatedand eventually removed from the kernel altogether.