On Fri, Aug 10, 2007 at 06:25:03PM +0200, Jan Kiszka wrote: > For this, I would suggest to start with analysing the TX and RX code > paths in normal Linux or -rt. User-triggered latency tracing or LTTng > might help. Then the next step would be a lock-dependency analysis. I > would be curious to hear about your findings.
Yup. > BTW, do you already use some of the emergency pool reservation patches > for this? I read interesting ideas recently on netdev, though no code > for those is written yet. Not yet, although I've followed the discussion with interest. We just made our first steps in that direction, so we don't have any rock-solid data yet. Today we tested with 'ping -f' load to rise interrupt load, and with /dev/zero -> netcat -> /dev/null traffic on the non-RT interfaces between the two RT boxes. The histograms don't look too different; with 1 hour of measure time it's still something like 320 us worst case round trip time. (I know that this is not representative, but anyway) > In any case, memory pressure should be part of your load scenarios. Next steps will be to apply default loads, like hackbench and cache calibrator. I'm not sure if low-memory situations are a real scenario, because on usual control systems you have a well defined set of applications which don't do much dynamic memory management. Nevertheless, it should be tested. Robert -- Dipl.-Ing. Robert Schwebel | http://www.pengutronix.de Pengutronix - Linux Solutions for Science and Industry Handelsregister: Amtsgericht Hildesheim, HRA 2686 Hannoversche Str. 2, 31134 Hildesheim, Germany Phone: +49-5121-206917-0 | Fax: +49-5121-206917-9 ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ RTnet-users mailing list RTnet-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/rtnet-users
