From: "Michael Chan" <[EMAIL PROTECTED]> Date: Tue, 31 Jan 2006 13:09:41 -0800
> Increase maximum receive ring size from 255 to 4080 by supporting > up to 16 linked pages of receive descriptors. To accomodate the > higher memory usage, each physical descriptor page is allocated > separately and the software ring that keeps track of the SKBs and the > DMA addresses is allocated using vmalloc. > > Some of the receive-related fields in the bp structure are re- > organized a bit for better locality of reference. > > Signed-off-by: Michael Chan <[EMAIL PROTECTED]> Why? To me, anything larger than 512 RX descriptors is overkill. It's a buffer, just like the queue of receive sockets for listening connections, and if you can't keep up then either: 1) Something is misdesigned or behaving badly 2) You lack the compute power to process the packet load And in either case the best thing to do is drop frames and not try to paper around the problem with huge RX descriptor counts. The complexity resulting from this expansion is yet another argument against this. And with Van Jacobson net channels, none of this is going to matter and 512 is going to be your limit whether you like it or not. So this short term complexity gain is doubly not justified. So, I definitely NAK this patch. - 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
