Messages in this thread | | | From | pwhiting@fury ... | Date | Thu, 8 Apr 1999 19:38:53 -0500 | Subject | Re: resolution.. |
| |
check out the utime patch:
http://hegel.ittc.ukans.edu/projects/utime/
pete
a cut from the document:
Linux, as well as most other operating systems maintain a sense of time using a periodic interrupt from a timer chip, which is known as the "heartbeat" of the system. The heartbeat of the Linux kernel is 10 ms for the i386 and 1ms for the DEC Alpha. In our efforts to impart real-time characteristics to the Linux kernel, such a coarse-grained timing mechanism was found to be insufficient.
Since we have concentrated on implementing UTIME for the i386, the rest of this document uses terms that are specific to the i386.
One of the ways to increase the temporal granularity of Linux would be to program the timer chip of the PC to interrupt the kernel at higher frequencies. This is not an acceptable solution as the overhead increase due to this is tremendous. For example, if we program the timer chip to interrupt the CPU at 40 micro-sec, the interrupt processing cost is so high there is no time left for any other computation. So, basically, we need to program the timer chip to generate interrupts only when there is some scheduled work that needs to be accomplished. This is what we have achieved.
On Thu, Apr 08, 1999 at 07:19:23PM -0400, arni@snafu.Rutgers.EDU wrote: > Hi, > The timer resolution on Linux with i386 is 10ms.. > > If I want a finer resolution.. how do I achieve that..?? > > Thanks, > Arni
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
| |