Subj : Re: JOB: Sandbridge Technologies, White Plains, NY
To   : comp.programming.threads
From : David Schwartz
Date : Fri Jul 15 2005 02:40 pm


"Joe Seigh" <jseigh_01@xemaps.com> wrote in message 
news:vf2dnT5FyZFAUUrfRVn-hw@comcast.com...

> I'm referring to pthread_cond_signal stuff.  Linux preempts the signaler
> which can slow things down considerably.  I've seen up to a 3x performance
> boost throwing in an extra sched_yield to "undo" the preemption on Linux.

    Fundamental rule: If there's any way you can allow a thread to keep 
running until it uses up its timeslice, do that. Only preempt a thread if 
that thread cannot make forward progress or you have a ready-to-run thread 
at a higher static priority or *much* higher dynamic priority.

    Do not ever preempt to create fairness! Each thread is entitled to its 
timeslice.

    DS

.