Valinor: Architectural Support for Fast, Energy-Efficient and Programmable Physical Memory Allocation

Konstantinos Kanellopoulos; Spiros Galanopoulos; Konstantinos Sgouras; Vlad-Petru Nitu; Ilias Papalamprou; Andreas Kosmas Kakolyris; Rahul Bera; Dimosthenis Masouros; Dimitrios Soudris; Onur Mutlu

arXiv · 2607.14789

Valinor: Architectural Support for Fast, Energy-Efficient and Programmable Physical Memory Allocation

Konstantinos Kanellopoulos·Spiros Galanopoulos·Konstantinos Sgouras·Vlad-Petru Nitu·Ilias Papalamprou·Andreas Kosmas Kakolyris·Rahul Bera·Dimosthenis Masouros·Dimitrios Soudris·Onur Mutlu

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Abstract

Physical memory allocation establishes virtual-to-physical mappings on demand. In current systems, each minor page fault traps into the kernel and triggers pipeline flushes, stalls, and a long sequence of allocation steps that can cost tens of thousands of cycles. These overheads are increasingly significant for short-lived workloads such as serverless functions and microservices, where minor faults can account for up to 54% of runtime and up to 40% of system energy. Prior hardware allocation proposals avoid traps and context switches, but either sacrifice useful placement optimizations or rely on fixed-function logic that cannot adapt to new policies or changing hardware conditions. We present Valinor, a hardware-OS cooperative memory allocation substrate that combines software flexibility with hardware-class performance. Valinor introduces a programmable hardware allocation engine that executes compact OS-supplied allocation libraries at close to fixed-hardware speed. It supports diverse policies, including short-lived object allocators, integrity mechanisms, and hardware-telemetry-guided placement. We implement Valinor on a BOOM RISC-V soft core running Linux and in a full-system simulator. On real hardware, Valinor accelerates allocation by 17x, improves end-to-end performance by 16%, and reduces energy consumption by up to 8%. Full-system simulation further evaluates the programmable allocation engine and six allocation libraries, showing that Valinor provides hardware-class performance without sacrificing programmability.

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Konstantinos Kanellopoulos, Spiros Galanopoulos, Konstantinos Sgouras, Vlad-Petru Nitu, Ilias Papalamprou, Andreas Kosmas Kakolyris, Rahul Bera, Dimosthenis Masouros, Dimitrios Soudris, Onur Mutlu. 2026-07-16. Valinor: Architectural Support for Fast, Energy-Efficient and Programmable Physical Memory Allocation. https://arxiv.org/abs/2607.14789

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