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A master's thesis from Aalborg University
Book cover


Energy-Aware Interface for Memory Allocation in Linux

Authors

;

Term

4. term

Education

Publication year

2021

Submitted on

Pages

78

Abstract

Dette speciale udvider Linux-kernen, så data der bruges ofte (varme data) og data der bruges sjældent (kolde data) kan placeres på forskellig hukommelseshardware. Målet er, at den hardware der rummer kolde data kan gå i lavenergitilstand og dermed spare strøm. Adskillelsen realiseres i kernen ved at tilføje en ekstra zone til kolde data, som kan konfigureres ved kompilering. Processer kan allokere hukommelse i den kolde zone via en udvidelse af systemkaldet mmap (bruges til at mappe hukommelse). Vi validerer hukommelseslayoutet med benchmarken STREAM og ser, at den ændrede kerne opfører sig som ønsket med hensyn til adskillelse af data. Derudover bygger vi en proof-of-concept database i hukommelsen for at måle strømforbrug og køretidsydelse. Resultaterne viser mindre overhead end forventet, men ingen reduktion i strømforbruget. Vi tilskriver det uændrede strømforbrug hukommelsescontrollerens strømhåndtering på vores testmaskine.

This thesis modifies the Linux kernel so that frequently used (hot) data and infrequently used (cold) data can be placed on different memory hardware. The aim is for the hardware holding cold data to enter low-power states and save energy. We implement this separation by adding a dedicated cold-data memory zone in the kernel, configurable at compile time. Applications can request memory from this cold zone through an extension to the mmap system call (used to map memory). We verify the intended placement with the STREAM benchmark and find that the modified kernel achieves the desired separation. We also build a proof-of-concept in-memory database to measure power consumption and runtime performance. The results show smaller performance overhead than expected, but no reduction in power usage. We attribute the unchanged power use to the memory controller’s power management strategy on our test machine.

[This abstract was generated with the help of AI]