Per-CPU PGDs...
Posted May 19, 2026 19:37 UTC (Tue) by Lionel_Debroux (subscriber, #30014)Parent article: In search of faster this_cpu operations
There's precedent for using per-CPU PGDs on Linux: PaX and therefore grsecurity have been using per-CPU PGDs, primarily beneath their KERNEXEC (~ x86 SMEP / ARM PXN, without hardware dependencies) and MEMORY_UDEREF (~ x86 SMAP / ARM PAN, again without hardware dependencies) anti-exploitation features, since well over a decade ago, long before CPUs grew some hardware acceleration: there are already occurrences of "PER_CPU_PGD" in a '2010 grsec patch I have lying around.