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

From: Chris Friesen (cfriesen@nortelnetworks.com)
Date: Thu May 08 2003 - 22:52:29 EST

Next message: Roland Dreier: "Re: how to measure scheduler latency on powerpc? realfeel doesn't work due to /dev/rtc issues"
Previous message: Xinwen Fu: "linksys workgroup switch works like a hub"
In reply to: Richard B. Johnson: "Re: how to measure scheduler latency on powerpc? realfeel doesn't work due to /dev/rtc issues"
Next in thread: Roland Dreier: "Re: how to measure scheduler latency on powerpc? realfeel doesn't work due to /dev/rtc issues"
Reply: Roland Dreier: "Re: how to measure scheduler latency on powerpc? realfeel doesn't work due to /dev/rtc issues"
Reply: William Lee Irwin III: "Re: how to measure scheduler latency on powerpc? realfeel doesn't work due to /dev/rtc issues"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

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

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.

> Does it have a printer port like the Intel machines?

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.

Chris

-- Chris Friesen | MailStop: 043/33/F10 Nortel Networks | work: (613) 765-0557 3500 Carling Avenue | fax: (613) 765-2986 Nepean, ON K2H 8E9 Canada | email: cfriesen@nortelnetworks.com

- 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/

Next message: Roland Dreier: "Re: how to measure scheduler latency on powerpc? realfeel doesn't work due to /dev/rtc issues"
Previous message: Xinwen Fu: "linksys workgroup switch works like a hub"
In reply to: Richard B. Johnson: "Re: how to measure scheduler latency on powerpc? realfeel doesn't work due to /dev/rtc issues"
Next in thread: Roland Dreier: "Re: how to measure scheduler latency on powerpc? realfeel doesn't work due to /dev/rtc issues"
Reply: Roland Dreier: "Re: how to measure scheduler latency on powerpc? realfeel doesn't work due to /dev/rtc issues"
Reply: William Lee Irwin III: "Re: how to measure scheduler latency on powerpc? realfeel doesn't work due to /dev/rtc issues"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

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