Operating Systems COT 4600 –Fall 2009Dan C. MarinescuOffice: HEC 439 BOffice hours: Tu, Th 3:00-4:00 PM Slides by Kaashoek & Morrisz Last time:z Systems and Complexityz Sources of Complexityz Todayz Knowledge and ethics. z Modularity, Abstractions, Layering, Hierarchy(slides from Lecture 1)z Computer Systems (slides by Kaashoek & Morris)z Next time:z Computer Systems versus Other Systemsz Coping with Computer System ComplexitySlides by Kaashoek & MorrisComposibility via static disciplinez Be tolerant of inputs and strict on outputsSlides by Kaashoek & MorrisMoore’s law“Cramming More Components Onto Integrated Circuits”, Electronics, April 1965cost per transistortransistors per dieSlides by Kaashoek & MorrisTransistors/die doubles every ~18 monthsSlides by Kaashoek & MorrisLithography: the driver behind transistor count• Components/area O(x2) with feature size• Total components O(a) with die area• Switching rate O(x) with feature sizeSlides by Kaashoek & MorrisCPU performanceSlides by Kaashoek & MorrisDRAM densitySlides by Kaashoek & MorrisDisk: Price per GByte drops at ~30-35% per yearSlides by Kaashoek & MorrisENIAC• 1946•Only one built• 5000 adds/sec• 20 10-digit registers• 18,000 vacuum tubes• 124,500 watts• Not really stored programSlides by Kaashoek & MorrisUNIVAC (Universal Automatic Computer)z 1951z 46 soldz 2000 ops/secz 1,000 12-digit words (mercury)z 5000 tubesz $1.5 millionSlides by Kaashoek & MorrisIBM System/360-40z 1964z 1.6 MHzz 16-256 KB corez $225,000z Family of sixz 32-bitz Time-sharingSlides by Kaashoek & MorrisCray 1: supercomputerz 1976z 80 soldz 80 MHzz 8 MbyteSRAMz 230,000 gatesz $5 millionSlides by Kaashoek & MorrisDEC PDP-8 (1964)z 60,000 soldz 330,000 adds/sec• 4096 12-bit words• $18,000Slides by Kaashoek & MorrisApple IIz 1977z 1 MHzz 6502 microprocessorz 4 to 48 Kilobytes RAMz $1300z Basic, VisicalcSlides by Kaashoek & MorrisIBM’s wrist watchz 2001z Linux and X11z 74 Mhz CPUz 8 Megabyte flashz 8 Megabyte DRAMz WirelessSlides by Kaashoek & MorrisSoftware follows hardware0102030405060Windows 3.1 (1992)Windows NT (1992)Solaris (1998)Windows 95Windows 98Windows NT 5.0 (1998)RedHat Linux 6.2 (2000)RedHat Linux 7.1 (2001)Windows XPVistaMillions of lines of source codeSlides by Kaashoek & MorrisCheap → PervasiveSlides by Kaashoek & MorrisPervasive → qualitative changeyearlog (people per computer)Slide from David Culler, UC BerkeleyNumber crunchingEmbeddedSense/controlWord processingCommunicationSlides by Kaashoek & MorrisLatency improves slowly11010010001234567891011Year #Improvement wrt year #1Moore’s law (~70% per year)DRAM access latency (~7% per year)Speed of light(0% per year)Slides by Kaashoek & MorrisHeat is a problemSlides by Kaashoek & MorrisRecent Intel CPU Clock Rates486PentiumPentiumProPentium IIIPentium 4Pentium 4 HTmHzSlides by Kaashoek & MorrisThe Future: will it be painful?AMD Barcelona Quad-core chipSlides by Kaashoek & MorrisWhat went right?z Unbounded composibilityz General-purpose computersz Only need to make one thing fastz Separate architecture from implementationz S/W can exploit new H/Wz Cumulative R&D investment over