Alexander Halbuer (M.Sc.)

Wissenschaftlicher Mitarbeiter


Telefon
0511 762 19729

E-mail
halbuer@sra.uni-hannover.de

Adresse
30167 Hannover
Appelstraße 4

Raum
Raum 119

Projects

ParPerOS: Parallel Persistency OS (DFG: LO 1719/8-1 and DI 2840/2-1)
In ParPerOS, we examine new abstractions for unified but efficient and optionally crash-consistent low-level memory management for data objects in heterogeneous memory systems that consist of volatile, persistent, distributed and other types of main memory.

Publications

2023

DIMES Workshop
Morsels: Explicit Virtual Memory Objects
Alexander Halbuer, Christian Dietrich, Florian Rommel, Daniel LohmannProceedings of the 1st Workshop on Disruptive Memory SystemsAssociation for Computing Machinery2023.
PDF Details Slides 10.1145/3609308.3625267 [BibTex]
USENIX Conference A Distinguished Artifact Award
LLFree: Scalable and Optionally-Persistent Page-Frame Allocation
Lars Wrenger, Florian Rommel, Alexander Halbuer, Christian Dietrich, Daniel Lohmann2023 USENIX Annual Technical Conference (USENIX '23)USENIX Association2023Distinguished Artifact Award.
PDF Details Slides [BibTex]

Teaching

Supervised Theses

Open Theses Topics

Efficient Swapping of Shared Virtual-Memory Objects

By design, morsels exist in main memory without being just an intermediate representation of a file. However, for some applications it would be desirable to store objects on a disk in order to persist its data during reboots or to cope with limited main memory.

 
Typ
Bachelorarbeit

 
Status
offen

 
Supervisors
Alexander Halbuer
Daniel Lohmann

 
Project
ParPerOS

Running Theses

Efficient Copy-on-Write for Virtual-Memory Objects

Implementing classical, full-featured COW with multiple nesting levels would introduce substantial management overhead on the operating system side. Our goal with Morsels is to eliminate this overhead while retaining limited COW functionality.

 
Typ
Masterarbeit

 
Status
laufend

 
Supervisors
Alexander Halbuer
Daniel Lohmann

 
Project
ParPerOS

 
Bearbeiter
Pasha Fistanto

Huge Pages for Virtual-Memory Objects

Currently, Morsels only support 4-KiB pages, but with larger page sizes the management overhead could be further reduced and the average memory access could be sped up, due to faster page-table walks and an increased TLB coverage.

 
Typ
Bachelorarbeit

 
Status
laufend

 
Supervisors
Alexander Halbuer
Daniel Lohmann

 
Project
ParPerOS

 
Bearbeiter
Marko Bolowski

Optimizing Memory Metadata: Dynamic Allocation of Struct Pages in the Linux Kernel

Dynamically allocate a struct page in cases where it is needed and omit the memory overhead in cases where it is not.

 
Typ
Masterarbeit

 
Status
laufend

 
Supervisors
Lars Wrenger
Alexander Halbuer
Daniel Lohmann

 
Project
ParPerOS

 
Bearbeiter
Paul Aumann

Page Eviction for Shared Virtual-Memory Objects

The translation lookaside buffer (TLB) caches present page table entries, so that pages can not be unmapped by simply clearing the related page table entry. However, page eviction is vital for implementing advanced features like swapping and huge-page merging.

 
Typ
Masterarbeit

 
Status
laufend

 
Supervisors
Alexander Halbuer
Daniel Lohmann

 
Project
ParPerOS

 
Bearbeiter
Tim Hollmann

Finished Student Theses

Databases on NVRAM

Bringing the advantages of non-volatile memory to database applications using the new morsel memory primitive as efficient abstraction layer.

 
Typ
Bachelorarbeit

 
Status
abgeschlossen

 
Supervisors
Alexander Halbuer
Daniel Lohmann

 
Project
ParPerOS

 
Bearbeiter
Matthias Wormann (abgegeben: 02. Oct 2023)

Morsel Managment Layer: Making Morsels Actually Useful

Bringing the new morsel memory abstraction to applications.

 
Typ
Masterarbeit

 
Status
abgeschlossen

 
Supervisors
Alexander Halbuer
Daniel Lohmann

 
Project
ParPerOS

 
Bearbeiter
Darian Biastoch (abgegeben: 26. Oct 2023)

IOMMU-assisted Memory Management: Sharing Virtual Memory Objects for Efficient Computing

Efficient Memory Management for Modern Computing Systems: Sharing Morsel Virtual Memory Objects between Processors and Devices via IOMMU.

 
Typ
Masterarbeit

 
Status
abgeschlossen

 
Supervisors
Alexander Halbuer
Daniel Lohmann

 
Project
ParPerOS

 
Bearbeiter
Kenny Albes (abgegeben: 05. Dec 2023)

Efficient Serialization of Page-Table-Based Virtual Memory Objects

With the discontinuation of Intel Optane and persistent memory being rarely available in general, alternative solutions need to be considered. One approach is to persist virtual memory objects on disk when persistent memory is not available.

 
Typ
Bachelorarbeit

 
Status
abgeschlossen

 
Supervisors
Alexander Halbuer
Daniel Lohmann

 
Project
ParPerOS

Structured Design of LaTeX-Beamer Slides and their Presentation in Multi-Moniter Environments

Create and extend the software support for multi-monitor presentations and evaluate useful usage and application scenarios.

 
Typ
Bachelorarbeit

 
Status
abgeschlossen

 
Supervisors
Björn Fiedler
Alexander Halbuer
Daniel Lohmann

 
Bearbeiter
Simon Hermes

Own Thesis

Primitives and Abstractions for Self-Contained Virtual-Memory Areas in the Linux kernel

Implement the basic abstraction for self-contained virtual-address-space areas in Linux, by which we want to ease the allocation, the sharing, and the management of huge amounts of memory. [PDF]

 
Typ
Masterarbeit

 
Status
abgeschlossen

 
Supervisors
Lars Wrenger
Florian Rommel
Christian Dietrich
Daniel Lohmann

 
Project
ParPerOS

 
Bearbeiter
Alexander Halbuer (abgegeben: 16. Nov 2022)