• [$] 128-Bit page tables for Arm

    From LWN.net@86:200/23 to All on Fri Aug 14 06:40:09 2026
    The size of a processor's page-table entries directly limits how much
    physical memory that processor is able to access. Back in the 32-bit days, that limit was 4GB, an amount of memory that once seemed nearly infinite,
    but which would now struggle to hold a basic AI-enabled "hello world" app.
    The expansion to 64˙bits on most popular architectures would seem to
    have removed those limits now; some Arm systems, for example, can use
    56˙of those bits to access up to 72PB of memory. So it might be
    surprising that the Arm architecture is evolving to support even larger page-table entries (PTEs). This
    patch set from Anshuman Khandual adds support for 128-bit PTEs, but
    who will benefit from this capability is not entirely clear.

    https://lwn.net/Articles/1088125/
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