From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarek Poplawski Subject: Re: [PATCH v2] tcp: splice as many packets as possible at once Date: Fri, 6 Feb 2009 10:58:07 +0000 Message-ID: <20090206105807.GD4879@ff.dom.local> References: <20090202084358.GB4129@ff.dom.local> <20090202.235017.253437221.davem@davemloft.net> <20090203094108.GA4639@ff.dom.local> <20090205.235258.257422341.davem@davemloft.net> <20090206091034.GA4879@ff.dom.local> <20090206092326.GC6645@gondor.apana.org.au> <20090206095119.GC4879@ff.dom.local> <20090206102822.GB7175@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: David Miller , zbr@ioremap.net, w@1wt.eu, dada1@cosmosbay.com, ben@zeus.com, mingo@elte.hu, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, jens.axboe@oracle.com To: Herbert Xu Return-path: Content-Disposition: inline In-Reply-To: <20090206102822.GB7175@gondor.apana.org.au> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Fri, Feb 06, 2009 at 09:28:22PM +1100, Herbert Xu wrote: > On Fri, Feb 06, 2009 at 09:51:20AM +0000, Jarek Poplawski wrote: > > > > OK, but since there is not so much difference, and we need to waste > > it in some cases anyway, plus handle it later some special way, I'm > > a bit in doubt. > > Well the thing is cards that don't support SG on tx probably > don't support jumbo frames either. ?? I mean this 128 byte chunk would be hard to reuse after copying to skb->data, and if reused, we could miss this for some NICs on TX, so the whole packed would need a copy. BTW, David mentioned something simple like sk_sndmsg_page would be enough, but I guess not for these non-SG NICs. We have to allocate bigger chunks for them, so more fragmentation to handle. Cheers, Jarek P.