Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754189AbYLTTji (ORCPT ); Sat, 20 Dec 2008 14:39:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752735AbYLTTj0 (ORCPT ); Sat, 20 Dec 2008 14:39:26 -0500 Received: from gw.goop.org ([64.81.55.164]:41509 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752580AbYLTTjZ (ORCPT ); Sat, 20 Dec 2008 14:39:25 -0500 Message-ID: <494D49E6.9000703@goop.org> Date: Sat, 20 Dec 2008 11:39:18 -0800 From: Jeremy Fitzhardinge User-Agent: Thunderbird 2.0.0.18 (X11/20081119) MIME-Version: 1.0 To: Evgeniy Polyakov CC: Herbert Xu , Vladislav Bolkhovitin , linux-scsi@vger.kernel.org, James Bottomley , Andrew Morton , FUJITA Tomonori , Mike Christie , Jeff Garzik , Boaz Harrosh , Linus Torvalds , linux-kernel@vger.kernel.org, scst-devel@lists.sourceforge.net, Bart Van Assche , "Nicholas A. Bellinger" , netdev@vger.kernel.org, Rusty Russell , David Miller Subject: Re: [PATCH][RFC 23/23]: Support for zero-copy TCP transmit of user space data References: <494C0255.8010208@goop.org> <20081219220452.GB704@ioremap.net> <494C1E5E.7070809@goop.org> <20081219223314.GA2736@ioremap.net> <494C50BB.5030809@goop.org> <20081220020250.GA15064@gondor.apana.org.au> <494C8D57.7040808@goop.org> <20081220065105.GA16936@gondor.apana.org.au> <494CA226.9000200@goop.org> <20081220081045.GA17439@gondor.apana.org.au> <20081220103209.GA23632@ioremap.net> In-Reply-To: <20081220103209.GA23632@ioremap.net> X-Enigmail-Version: 0.95.6 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1068 Lines: 27 Evgeniy Polyakov wrote: > Things should work fine, since pskb_expand_head() copies whole shared > info structure (and thus will copy destructor), get all pages and then > copy all pointers into the new skb, and then release old skb's data. > > So destructor for the pages should not rely on which skb it is called on > and check if pages are about to be really freed (i.e. check theirs > reference counter). > OK. > __pskb_pull_tail() is tricky, it just puts some pages it does not want > to be present in the skb, but it could be possible to add there > destructor callback from the original skb with partial flag (or just > having destructor with two parameters: skb and page, and if page is not > NULL, then actually only given page is freed, otherwise the whole skb). > Yes, that doesn't sound too bad. J -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/