"Joefon Jann’s Web Page"
JOEFON JANN: Distinguished Engineer, IBM T.J.Watson Research Center, Yorktown Heights, NY, USA
AREAS OF RESEARCH: Systems Software (OS, hypervisor, systems management for clusters with availability), social graph analysis using linear algebra, security and PQC(Post Quantum Cryptography) optimizations for POWER systems
- BA: Wellesley College   (w/ MIT-cross registration), Mathematics, minor: Physics
- MA: CUNY, Mathematics
- MS: Columbia Univerisity, NY   School of Engineering, Computer Science
Related Scholarly Links:
- Google citations:   over 1252 citations
- Joefon in Wikipedia
- Deep Blue
The Jann Model of Massively Parallel Workloads
This is a compact and flexible model to represent the arrival times, and service times distribution of workloads at supercomputing centers. This is a phase-type (Hyper-Erlang)  probability distribution model. It is convenient for use in queueing-theory   based analyses. The model has very few parameters and they are analytically derivable from the observation of the workload. It is convenient to use this model to develop job schedulers for HPC datacenters. Parallel workload models Archive
- DLPAR (Dynamic Logical Partitioning) Wikipedia article
This work forms the fundamental building blocks for Virtualization for IBM POWER Servers since POWER4 (see also IBM Systems Journal paper).
- Multiple Concurrently Pageable Page-sizes in AIX -- yielding industry leading-edge performance
- Kernel Hot Patch -- the basis for the eFix manager for delivering Emergency patches for AIX
- AHAFS(Autonomic Health Advisor FileSystem) -- on which the PowerSC RTC(RealTime Compliance) offering is built
- RBAC(Role-Based Access Control) and framework in AIX -- Enhancing Security & ease-of-use for applications and OS administration
- Memory Keys Support in AIX in POWER6
- AIX AutoDiag tool -- which instaneously finds closest problems and lists their fixes, upon submission of an OS dump; using AI(Artificial Intelligence) techniques
- PQC(Post Quantum Cryptography) optimizations for IBM POWER systems
- PowerVM-SDN with video on youTube
The Jann Model of Massively Parallel Workloads
DLPAR article in Encyclopedia of Parallel Computing
- (DLPAR): Basic Building Blocks for Autonomic Computing in IBM pSeries Servers.
IBM Systems Journal's special issue on Autonomic Computing, Vol 42, No. 1, 2/2003.
- Graph Programming Interface of Sparse Matrices for Social Graphs -- now standardized in GraphBLAS
- Best paper: Towards an Immortal Operating System in Virtual Environments by Joefon Jann, et al
in the “Best of SBAC-PAD2012” issue of the Elsevier Journal of Parallel Processing
- Best paper award HiPC-1997: Lazy Home Migration for Distributed Shared Memory Systems
by Sandra Baylor, Kattamuri Ekanadham, Joefon Jann, Beng-Hong Lim & Pratap Pattnaik
- Book forward for the book titled "AIX Performance"
- IBM Journal of Research and Development paper titled "Advanced Features in POWER8 Systems" - 1/2015
- IBM Journal of Research and Devleopment paper titled "What's New in POWER9 System Software" - 7/2018
- Many others: Search for "Joefon Jann" in Google Scholar and in
Patents (reverse time order)
- Reducing memory access latency in scatter/gather operations, 05 Jan 2021.
- Sharing ownership of an input/output device using a device driver partition, 25 Aug 2020.
- Shared memory in a virtual environment, 16 Jun 2020.
- Invalidation of shared memory in a virtual environment, 30 Jul 2019.
- Extending trusted hypervisor functions with existing device drivers, 16 Jul 2019.
- Invalidation of shared memory in a virtual environment, 19 Feb 2019.
- Shared memory in a virtual environment, 08 Jan 2019.
- Software patch management incorporating sentiment analysis, 30 Oct 2018.
- Automated diagnosis of software crashes, 20 Aug 2018.
- Mitigating collisions in a physical space during gaming, 14 Nov 2017.
- Sophisticated run-time system for graph processing. 03 Oct 2017.
- Sophisticated run-time system for graph processing. 26 Sep 2017.
- Automated diagnosis of software crashes. 06 Sep 2016.
- Optimized system for analytics (graphs and sparse matrices) operations. 04 Apr 2016. US 9304835
- Method and apparatus for operating system event notification mechanism using file system interface. 13 Jan 2015. US 8935579
- System using a unique marker with each software code-block.30 Sep 2014.
- Method for reducing the time to diagnose the cause of unexpected changes to system files. 31 Dec 2013.
- System and method for supporting a plurality of access control list types for a file system in an operating. 23 Apr 2013. US 8429192
- Method and apparatus for operating system event notification mechanism using file system interface. 22 Mar 2013.
- Method and apparatus for operating system event notification mechanism using file system interface. 12 June 2012.
- Automated transition to a recovery kernel via firmware-assisted-dump flows providing automated operating system diagnosis and repair. 06 Mar 2012.
- Method and infrastructure for detecting and/or servicing a failing/failed operating system instance. 12 July 2011.
- Framework for managing attributes of objects. 22 Feb 2011.
- Method and structure for low memory relocation for dynamic memory reconfiguration. 10 Feb 2009.
- Method and mechanism for efficiently creating large virtual memory pages in a multiple page size environment. 14 Oct 2008.
- Method and apparatus for broadcasting messages with set priority to guarantee knowledge of a state within a data processing system. 05 Sep 2006.
- Secure partitioning of shared memory based multiprocessor system.12 Nov 2002.
- Home node migration for distributed shared memory systems. 13 Apr 1999.
- Additional 7+ Patent Applications filed ...
Alternate email: firstname.lastname@example.org
IBM T.J. Watson Research Center
1101 Kitchwan Road, Yorktown Heights,
NY 10598. USA