Re: how to measure scheduler latency on powerpc? realfeel doesn't work due to /dev/rtc issues

William Lee Irwin III
2003-05-09T04:14:32Z

On Thu, 8 May 2003, William Lee Irwin III wrote:
>>>>> Why would you want to use an interrupt? Just count jiffies in sched.c

On Thu, May 08, 2003 at 11:52:29PM -0400, Chris Friesen wrote:
> I'm trying to get a feel for the maximum time from an interrupt coming in
> until the userspace handler gets notified. On intel you can program the
> hardware to generate interupts through /dev/rtc. The powerpc doesn't seem
> to support this.
> Jiffies are not accurate enough, I am expecting max latencies in the 1-2 ms
> range.
> Unfortunately no. USB/Firewire/Ethernet on the desktop, ethernet/serial
> for compactPCI.
> I want to find an additional programmable interrupt source. It bites that
> cheap PCs have this, and the powerpc doesn't.

Try the timebase instead.

-- wli