On Wednesday 15 June 2005 12:34 pm, Alan Stern wrote: > You may be interested in the sequence of messages starting here: > > http://lists.parisc-linux.org/pipermail/parisc-linux/2005-June/026623.html > > According to Grant Grundler, "...networking folks are trying > to set precedent that unaligned access macros should go away. > That is despite clear evidence of substantial performance improvements > on RISC arches."
This is all third-hand information ... though FWIW I've always had the impression the networking policy was too extreme in that area. They don't want drivers handing them unaligned packets, OK so be it ... but then they should be failing obviously when drivers do that. One "if (unlikely(addr wrongly aligned))" at packet ingress would remove a lot of nastiness; it's possible to be a bit too focused on nano-metrics of performance. For this specific USB problem the fix is straightforward, and doesn't need to involve unaligned access. The "packed" decl, in conjunction with the policy of leaving descriptors in "wire" byteorder, can remove this problem... - Dave ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
