From: Herbert Xu <[EMAIL PROTECTED]> Date: Fri, 1 Dec 2006 15:37:55 +1100
> So in general when allocating packets we have two scenarios: > > 1) The dst is known and fixed, i.e., all datagram protocols. This is > the easy case where the headroom is known exactly beforehand. > > 2) The dst is unknown or may vary, this includes TCP, SCTP and DCCP. > This is where we currently use MAX_HEADER plus some protocol-specific > headroom. > > Right now the normal (non-IPsec) dst output path always checks for > sufficient headroom and reallocates if necessary (ip_finish_output2). > I propose that we make IPsec do the same thing. Agreed. > For standard MTU-sized packets this discussion is moot since we have > 2K of memory in each chunk. However, for ACKs it could save a bit of > memory. For linear MTU-sized SKBs yes, but TCP data packets are going out %99 of the time with paged data these days and thus suffers from the same set of issues and potential savings. - 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
