On Wed, 18 Jul 2007 13:13:21 -0400 Roy Pledge <[EMAIL PROTECTED]> wrote:
> Stephen Hemminger wrote: > > > > You could play tricks with skb frags but it would be fragile > > and not worth the trouble. The problem is that the receive > > skb can stay in the system for a really long time (until the application > > reads the data) so your fixed size buffer pool in hardware > > would get exhausted. > > > Perhaps you could elaborate on why this is considered fragile? It seems to > me > that as long as proper page management is performed, this mechanism should be > stable for processing non-contiguous receive buffers. I agree that > replenishment needs to be addressed, but I see that as an independent issue > from > using frag lists on receive. Imagine you had a 4MB receive area. If you used fraglist to point to the data area, you would still be at risk of receive lock up when you have all the receive area used up in skb's waiting in the receive queue of the sockets. You might get it to work if the receive are was very large (ie much larger than tcp_rmem), but at that point you might as well as be able to access all of system memory. Using a DMA I/O engine would help, but you probably won't have one available. - 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
