From mboxrd@z Thu Jan 1 00:00:00 1970 From: Evgeniy Polyakov Subject: Re: problems with e1000 and jumboframes Date: Sat, 5 Aug 2006 14:24:36 +0400 Message-ID: <20060805102435.GA15740@2ka.mipt.ru> References: <41b516cb0608031334s6e159e99tb749240f44ae608d@mail.gmail.com> <20060804061513.GB413@2ka.mipt.ru> <41b516cb0608040834o1d433f23v2f2ba1a1b05ccbc6@mail.gmail.com> <20060804194209.GA25167@2ka.mipt.ru> <4807377b0608041402p10149bfbrd9e5f3b8849d3f56@mail.gmail.com> <20060805095846.GA17867@2ka.mipt.ru> <20060805100954.GB20939@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=koi8-r Cc: Jesse Brandeburg , Chris Leech , arnd@arndnet.de, olel@ans.pl, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Return-path: Received: from relay.2ka.mipt.ru ([194.85.82.65]:9440 "EHLO 2ka.mipt.ru") by vger.kernel.org with ESMTP id S1422808AbWHEKZB (ORCPT ); Sat, 5 Aug 2006 06:25:01 -0400 To: Herbert Xu Content-Disposition: inline In-Reply-To: <20060805100954.GB20939@gondor.apana.org.au> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Sat, Aug 05, 2006 at 08:09:54PM +1000, Herbert Xu (herbert@gondor.apana.org.au) wrote: > > If you can create several skbs and link them togeter you defenitely can > > organize pages into frag_list, just get pages from different skb->data > > and free those skbs. > > Having a more flexible mechanism for managing skb_shared_info->frags > would definitely be an improvement. At the moment we can't indicate > whether the individual frags are writable so we assume every frag to > be read-only. Having one page inside frag_list writable does not make a lot of sence, so we really need either all of them writable, or nothing. And it is much less error-prone to assume that every page is read-only. > If we had a flag to indicate writability we could also have a flag to > indicate that the memory comes from kmalloc rather than alloc_page. Yes, that would be good, but who will give us a bit in the struct page? Can we recreate frag_list elements to be a bitmasks and steal couple of them there, so we would not increase fragment's structure size? > Cheers, > -- > Visit Openswan at http://www.openswan.org/ > Email: Herbert Xu ~{PmV>HI~} > Home Page: http://gondor.apana.org.au/~herbert/ > PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt -- Evgeniy Polyakov