keeping simple

Category: systems

  • memories

    For some reason, all copies of an early variant of RTLinux called “myrtlinux” by its Italian “author” have disappeared from the web, but thanks to some archives we can find some fragments from old days.  For example, within a year or two of this email, the story had changed rather  dramatically. To me, there were…

  • Microsoft by the numbers

    From correspondent AY: 150,000,000 Number of Windows 7 licenses sold, making Windows 7 by far the fastest growing operating system in history. <10 Percentage of US netbooks running Windows in 2008. 96 Percentage of US netbooks running Windows in 2009. 9,000,000 Number of customer downloads of the Office 2010 beta prior to launch, the largest…

  • Toyota’s problem: hardware weenies and poor accounting practices [updated]

    Jamie Kitman’s look at the twisted path Toyota followed to it’s current difficulties inspired me to think about software and money – two topics I spend way too much time thinking about. As a purely disinterested observer (ahem) it has come to my attention, repeatedly, that manufacturing companies undervalue, underinvest in, and undertest software.  On…

  • Linux semaphores

    Re: Schedule idle MOLNAR Ingo (mingo@chiara.csoma.elte.hu) Wed, 11 Nov 1998 04:09:32 +0100 (CET) […] > _please_ We can do better than this. Only semaphores (not spinlocks) need > to have the priority inheritance. […] nope there are _not_ only semaphores, but many other types of locks. > […] This can be done with lists off…

  • Security for dummies – a lesson for smart grid

    WASHINGTON — Militants in Iraq have used $26 off-the-shelf software to intercept live video feeds from U.S. Predator drones, potentially providing them with information they need to evade or monitor U.S. military operations. Senior defense and intelligence officials said Iranian-backed insurgents intercepted the video feeds by taking advantage of an unprotected communications link in some…

  • multicore and multiprocessor performance

    Here’s two  interesting tables Percentage of lock acquisitions for global TCP/IP locks that do not succeed immediately. OS Type 6 conns 192 conns 16384 conns MsgP 89 100 100 ConnP-L(4) 60 56 52 ConnP-L(8) 51 30 26 ConnP-L(16) 49 18 14 ConnP-L(32) 41 10 7 ConnP-L(64) 37 6 4 ConnP-L(128) 33 5 2 L2 Data…

  • The ridiculous GPL-only tagging of Linux

    Imagine that you release software under a license that is primarily concerned with making sure that modifiable source code is available to all and that no restrictions should ever be placed on derived works. Now imagine that someone takes a huge body of code like this and starts marking interfaces as limited to specific uses…

  • 10th anniversary of the RTLinux Manifesto paper

    The RTLinux* Manifesto was published a little over 10 years ago at the 5th Linux Expo in Raleigh North Carolina which was really the first one with a bunch of suits wandering around.  As a kind of celebration/experiment , I’m publishing an annotated version. Here is a related discussion . * RTLnux is a  trademark…

  • More petty

    The ALMA team has released ACS 8.0 on Red Hat 4.4, downgrading the Linux version from the foreseen 5.2 version. This choice, with the consequent back-porting of the code to the older OS version, had to be taken because of major problems encountered by the Control and Correlator teams in porting RTAI real time code…

  • Parallelism and multicore

    The goal of modern processor chip design has changed from optimizing various speed/price/heat tradeoffs for applications to finding excuses for dumping more transistors into the device.  Heard an interesting talk from Krisztián Flautner of ARM at the ACISC conference and I have to admit that it’s not entirely the fault of the chip designers –…