Subj : Re: Optimizing for latency
To   : comp.programming.threads
From : David Schwartz
Date : Tue Jun 07 2005 01:16 pm


<scream29125@yahoo.com> wrote in message 
news:1118171388.006430.189540@g44g2000cwa.googlegroups.com...

> Sorry, I forgot to mention that synchronization between the CPU and the
> devices is interrupt-driven. This is why the CPU is idle most of the
> time when it is waiting for the device to respond.

    How does the process wait for an interrupt?

> Additional info:
>
> In setup #2, to verify my code, I forced the devices to be active only
> one at a time (only 1 thread running at a time), jobs take 100-200ms
> each. This is the same timing I get in setup #1 too. However when I
> allow 4 devices to run concurrently (4 threads active) in setup #2,
> jobs take 200-400ms.

    What are the threads doing when they're not actively servicing a device?

    DS

.