On 9/6/07, Sam Fourman Jr. <[EMAIL PROTECTED]> wrote: > hello misc@ > from the page http://www.openbsd.org/42.html , one of the changes made > to OpenBSD 4.2 is > > A change in the way the kernel random pool is stirred greatly > increases performance with network interface cards that support > interrupt mitigation, especially on architectures where reading the > clock is expensive (such as amd64). > > What would be some Examples of Network Cards that Support "interrupt > mitigation" > > I guess on this Subject I need educated because I am not all together > sure what interrupt mitigation is and why I want it.
I'm not the right person to try to explain it, but I have generally been interested in seeing where it crops up and what it's associated with. The various /plusXY.html pages often have notes indicating drivers for which interrupt mitigation has been enabled/enhanced, and you can see what generally has it. For example, from plus38.html: "Add microcode to support interrupt mitigation on fxp(4) 82551 F stepping chipset. Big performance boost." plus39.html: "Fix for the nfe(4) interrupt mitigation code." ...or a CVS commit about enabling it in a National Semiconductor chip: http://marc.info/?l=openbsd-cvs&m=118037514315592&w=2 ...after which Soekris boxen with the DP83816 chips could experience better throughput at lower interrupt rates, good since the poor thing's CPU is a limiting factor. It's fun to look for this kind of stuff in the CVS commit logs, e.g. http://marc.info/?l=openbsd-cvs&w=2&r=1&s=%22interrupt+mitigation%22&q=b http://marc.info/?l=openbsd-cvs&w=2&r=1&s=%22interrupt+holdoff%22&q=b http://marc.info/?l=openbsd-cvs&w=2&r=1&s=interrupt+coalesce&q=b and other places: http://www.openbsd.org/papers/cuug2007/mgp00016.txt DS
