Experience

Harmonic

• United States
• IT Services and IT Consulting
• 1 - 100 Employee

• Senior Staff Software Development Engineer

  • Mar 2014 - Jan 2018

  San Jose, CA



Panasas

• United States
• Software Development
• 1 - 100 Employee

• Software Engineer

  • Oct 2012 - Oct 2013

  Sunnyvale, CA Projects worked on: • Backport of FreeBSD 9.0 CAM/ATA and AHCI driver supporting NCQ to FreeBSD 7.2 kernel: Implemented enhancements for control of advanced SSD features. Implemented performance measurement hooks within driver and internal performance tests. Carried out performance qualification testing using SPECsfs2008 and internal performance tests. • FreeBSD 7.2 direct mapped buf: Investigated buf usage within geom and driver layers. Implemented direct mapped buf allocation and… Show more Projects worked on: • Backport of FreeBSD 9.0 CAM/ATA and AHCI driver supporting NCQ to FreeBSD 7.2 kernel: Implemented enhancements for control of advanced SSD features. Implemented performance measurement hooks within driver and internal performance tests. Carried out performance qualification testing using SPECsfs2008 and internal performance tests. • FreeBSD 7.2 direct mapped buf: Investigated buf usage within geom and driver layers. Implemented direct mapped buf allocation and access functions. Show less



Hewlett-Packard

• United States
• Information Technology & Services
• 300 - 400 Employee

• Linux/HP-UX Kernel Engineer

  • Aug 1996 - Aug 2012

  Cupertino, CA 2012: Responsible for Mission Critical Linux Scaling. 1996-2011: Technical lead on a variety of long and short term projects. Worked with global, cross functional and inter-company teams to build, enhance and maintain HP-UX. Highlights of significant contributions include: New HP-UX API: Spearheaded investigation of changes needed to fundamental constants, types and limits to define new API to allow better scaling. New API had to conform to many standards, resolve conflicts between… Show more 2012: Responsible for Mission Critical Linux Scaling. 1996-2011: Technical lead on a variety of long and short term projects. Worked with global, cross functional and inter-company teams to build, enhance and maintain HP-UX. Highlights of significant contributions include: New HP-UX API: Spearheaded investigation of changes needed to fundamental constants, types and limits to define new API to allow better scaling. New API had to conform to many standards, resolve conflicts between them and do so in a maintainable, extensible manner to accommodate future standards. Proposed specific changes and coordinated review by partners. Header File Architect, Lab Compatibility Champion and Standards Consultant: Deep knowledge of ANSI C(’89,’99), IEEE Std 1003.1 (POSIX) (‘88-‘08), Single Unix Specification (Unix ’95 – Unix 2010). System Call Infrastructure Architect: Responsible for HP-UX system call infrastructure, context switching, lazy FP save/restore, context switch paravirtualization, thread/process initialization, signal delivery and other subsystems related to thread/process management. Lead investigation/prototype of system call infrastructure renovation to enable better performance and add multiple API/ABI support. Implemented hand-optimized assembly versions of performance sensitive system calls. User Identity/Security Credential Rearchitecture: Redesigned locking and sharing to remove performance bottlenecks. Rewrote credential services separating mechanism from policy to enable expanded groups list and major new security features while maintaining future binary compatibility. Implemented changes to code belonging to more than a dozen global partners to seamlessly eliminate data dependencies on this and other projects. Also worked on: pthreads (kernel and library), profiling services, clock/timer, kernel/user-space synchronization mechanisms, IPC mechanisms... Inventor: Patent 7,797,505 (Program Stack Handling)

• Domain/OS, HP-UX Kernel Engineer

  • May 1989 - Aug 1996

  Chemsford, MA 1993-1996: HP-UX Kernel Engineer. Modified/maintained substantial perl script to mirror kernel source changes between proprietary RCS based SCM to ClearCase. 1989-1993: Domain/OS Kernel and System Library engineer. Member of IEEE 1003.1c-1995 (POSIX Threads) balloting committee.



Apollo Computer

• United States
• Computer and Network Security
• 1 - 100 Employee

• System Software Engineer

  • Aug 1988 - Apr 1989

  Chelmsford, MA Apollo acquired by Hewlett-Packard in May 1989. Responsible for C library, other global libraries and streams managers used to implement BSD and System V UNIX environments in Domain/OS.



NECIS

• Software Engineer

  • Dec 1986 - Aug 1988

  NEC Information Systems - an American subsidiary of NEC Japan Responsible for implementaton of BSD kernel features in System V.2 kernel (NEC/IX)



GCA/Tropel

• Member of Technical Staff

  • Sep 1985 - Oct 1986

  Responsible for porting and maintenance of System V UNIX commands and libraries to in-house V7 based system (TROPIX). Also responsible for installation/operation of in-house UUCP and ethernet networks, external UUCP connections, USENET.