From: Stephen Hemminger <[EMAIL PROTECTED]> Date: Thu, 5 Jul 2007 17:00:51 -0700
> On Thu, 05 Jul 2007 16:43:08 -0700 (PDT) > David Miller <[EMAIL PROTECTED]> wrote: > > > From: Stephen Hemminger <[EMAIL PROTECTED]> > > Date: Thu, 05 Jul 2007 16:14:14 -0700 > > > > > The scatterlist only needs 16 bits for length/offset because > > > PAGE_SIZE is 4K > > > > > > Signed-off-by: Stephen Hemminger <[EMAIL PROTECTED]> > > > > Unfortunately I don't think this can be done, even on i386. > > > > It is legal to use order!=0 pages and multi-page areas in a single > > scatterlist entry. > > > > Okay, but then using SG lists makes skbuff's much bigger. > > fraglist scatterlist per skbuff > 32 bit 8 20 +12 * 18 = +216! > 64 bit 16 32 +16 * 18 = +288 > > So never mind... I know, this is why nobody ever really tries to tackle this. > I'll do a fraglist to scatter list set of routines, but not sure > if it's worth it. It's better to add dma_map_skb() et al. interfaces to be honest. Also even with the scatterlist idea, we'd still need to do two map calls, one for skb->data and one for the page vector. - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
