Libtorque

My project for Professor Rich Vuduc's Fall 2009 CSE6230, libtorque is a multithreaded event library for UNIX designed to take full advantage of the manycore, heterogenous, NUMA future. Previous, non-threaded event libraries include libevent, libev and liboop. My project proposal suggests motivation for libtorque: I believe it necessary to take scheduling and memory-placement decisions into account to most optimally handle events, especially on manycore machines and especially to handle unexpected traffic sets (denial of service attacks, oversubscribed pipes, mixed-latency connections, etc).

Resources

• git hosting from GitHub:
  • Available from the dankamongmen/libtorque project page
  • git clone from git://github.com/dankamongmen/libtorque.git
• bugzilla, hosted here on http://dank.qemfd.net/bugzilla/

Milestones

• 2009-11-19: CSE 6230 checkpoint
• 2009-12-10: CSE 6230 due date

Design/Functionality

System discovery

• Full support for CPUID as most recently defined by Intel and AMD (more advanced, as of 2009-10-31, than x86info)
• Full support for [Linux APIs|Linux] and [FreeBSD APIs|FreeBSD's] native cpuset libraries, and SGI's libcpuset and [libNUMA]
• Discovers and makes available, for each processor type:
  • ISA, ISA-specific capabilities, and number of concurrent threads supported (degrees of SMT)
  • Line count, associativity, line length, geometry, and type of all caches
  • Entry count, associativity, page size and type of all TLBs
  • Inclusiveness relationships among cache and TLB levels
  • APIC ID's and how caches are shared among them
  • More: properties of hardware prefetching, ability to support non-temporal loads (MOVNTDQA, PREFETCHNTA, etc)
• Discovers and makes available, for each memory node type:
  • Connected processor groups and relative distance information
  • Number of pages and bank geometry
  • More: OS page prefetching policy, error-recovery info

References/Prior Art

• Philip Mucci's "Linux Multicore Performance Analysis and Optimization in a Nutshell", delivered at NOTUR 2009
• Elmeleegy et al's "Lazy Asynchronous I/O", USENIX 2004
• PGAS: Kathy Yelick's "Performance and Productivity Opportunities using Global Address Space Programming Models", 2006
• Emery Berger's Hoard and other manycore-capable allocators (libumem aka magazined slab, Google's ctmalloc, etc).

888 ,e, 888        d8           "...tear the roof off the sucka..."
888  "  888 88e   d88    e88 88e  888,8,  e88 888 8888 8888  ,e e,
888 888 888 888b d88888 d888 888b 888 "  d888 888 8888 8888 d88 88b
888 888 888 888P  888   Y888 888P 888    Y888 888 Y888 888P 888   ,
888 888 888 88"   888    "88 88"  888     "88 888  "88 88"   "YeeP"
_____________________________________________ 888 _________________
continuation-based unix i/o for manycore numa\888/© nick black 2009