Why Not Sixty-Four Kilobytes

An architect proposes raising the system's only page size from 4 KiB to 64 KiB. Two of the arguments are simply true: a linear page table for a given address space shrinks by a factor of 16, and a TLB of the same entry count covers 16 times as much memory.

What is the strongest argument against making 64 KiB the universal default?

The TLB has to be flushed more often on a context switch, because one entry now covers memory that belongs to more than one process.

Every mapping rounds up to a multiple of 64 KiB, so a machine running hundreds of small processes and libraries loses the unused tail of each region, and every demand fault now pulls 64 KiB from storage.

External fragmentation of physical memory returns, because a 64 KiB frame has to be found as a contiguous run of free memory rather than assembled from whatever is free.

The page table needs more levels to cover the same address space, so every TLB miss costs an extra dependent memory read before the translation lands.