Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755547AbZGCKVY (ORCPT ); Fri, 3 Jul 2009 06:21:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752102AbZGCKVR (ORCPT ); Fri, 3 Jul 2009 06:21:17 -0400 Received: from mail-px0-f190.google.com ([209.85.216.190]:51457 "EHLO mail-px0-f190.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751425AbZGCKVQ (ORCPT ); Fri, 3 Jul 2009 06:21:16 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=pfNDM7IZ3iCKRr/xd3XbWT60sk2v3so1lKEh83J8j9PC+w5hyERgzpZKoVuxN+ZONJ Pz0qvAHHyo+vQtFf5QT8ActQ4aNnfjiz4ZhmKu3S9XB+rYakRsJqOeb5iqVsxAw+nVNr 3U10k0JwmLksHh1jl3yDTHR34/ZLIdQf+CZaY= Date: Fri, 3 Jul 2009 18:23:25 +0800 From: Amerigo Wang To: Changli Gao Cc: Amerigo Wang , Linus Torvalds , Linux Kernel Mailing List Subject: Re: PROPOSAL: extend pipe() to support NULL argument. Message-ID: <20090703102325.GK5880@cr0.nay.redhat.com> References: <20090703030008.GD5880@cr0.nay.redhat.com> <412e6f7f0907022108p7c533ed2wd16fceb0f282ed62@mail.gmail.com> <20090703051917.GE5880@cr0.nay.redhat.com> <412e6f7f0907022242r52ad981fyd51c2a55f41ab228@mail.gmail.com> <20090703071504.GG5880@cr0.nay.redhat.com> <412e6f7f0907030040v6133badat7058186a01d78f44@mail.gmail.com> <20090703081655.GH5880@cr0.nay.redhat.com> <412e6f7f0907030127u3d6806dfo9168600e7c71b241@mail.gmail.com> <20090703094229.GI5880@cr0.nay.redhat.com> <412e6f7f0907030259m5556ee2fobbb58d377bce4d17@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <412e6f7f0907030259m5556ee2fobbb58d377bce4d17@mail.gmail.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1175 Lines: 34 On Fri, Jul 03, 2009 at 05:59:10PM +0800, Changli Gao wrote: >On Fri, Jul 3, 2009 at 5:42 PM, Amerigo Wang wrote: >>>I said: It just a special case. Fixing sendfile() won't fix everything. >> >> What do you want? Just saving an fd, isn't it? >> >> sendfile() does this but you said it's buggy, if you fix it, what is the >> rest problem? >> >You should know why Linux invented splice(2). Not all of the problems >can be solved by sendfile(2). Sure, it definitely can be seen from the interface.... > >>> >>>In fact, sendfile(2) is implemented via splice(2) infrastructure. The >>>logic is the same, and much clever than yours. Dive into its code, you >>>will find the reason why it must be blocked on outfd. >> >> >> Sure, this is done in user-space, definitely.... >> >Did you review the code of sendfile(2)? Not at all. I just wanted to show what I wanted to say, not to re-implement sendfile(2). -- 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/