[lkml]   [1999]   [Jul]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: kernel thread support - LWP's
    On Thu, Jul 15, 1999 at 03:04:23PM -0400, Benjamin LaHaise wrote:
    > On Thu, 15 Jul 1999, Nate Tuck wrote:
    > > In cases where developer time (or time to market) is at a premium and the
    > > problems at hand require some kind of modular parallelism. I have a
    > > program on my desk that can run >20 active threads on a one CPU machine.
    > > Given the problem(s) we had to solve with it, threads saved us many
    > > man-months of development effort and were the right answer. I can imagine
    > > that other developers have the same sorts of quandaries (or would if they
    > > understood how threads could help them).
    > I'll agree with you on the cost side of things, but are you certain that
    > the model used for the application is correct? That is what I'm
    > questioning, not the fact that your app can trigger >20 active threads.
    > An event driven system can be worked on by just as many programmers as a
    > threads based systems.

    I don't think the modularity was referring to had anything to do with
    multiple developers. I expect that he had several independent modules,
    which could/should execute in parallel, and each of which had some amount
    of state. By using multiple threads, it is frequently possible to
    implicitly keep track of this state in a thread's stack.

    To switch to an event-based model, that implicit state would have to be
    explitly saved and restored when processing other events. Depending on
    the application, that state could be arbitrarily complex, and
    saving/restoring it could be hard to do quickly and correctly. Once
    you've written all the save/restore code, you've essentially written your
    own special-purpose user-level threading library, and each 'event' is
    really just a 'context switch'.

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 13:53    [W:0.025 / U:0.072 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site