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

From: William Lee Irwin III (wli@holomorphy.com)
Date: Thu May 08 2003 - 23:26:59 EST


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
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Thu May 15 2003 - 22:00:30 EST