From owner-svn-src-all@FreeBSD.ORG Tue Oct 23 16:39:04 2012 Return-Path: Delivered-To: svn-src-all@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 230A01B2 for ; Tue, 23 Oct 2012 16:39:04 +0000 (UTC) (envelope-from andre@freebsd.org) Received: from c00l3r.networx.ch (c00l3r.networx.ch [62.48.2.2]) by mx1.freebsd.org (Postfix) with ESMTP id 825098FC1B for ; Tue, 23 Oct 2012 16:39:03 +0000 (UTC) Received: (qmail 86564 invoked from network); 23 Oct 2012 18:17:02 -0000 Received: from c00l3r.networx.ch (HELO [127.0.0.1]) ([62.48.2.2]) (envelope-sender ) by c00l3r.networx.ch (qmail-ldap-1.03) with SMTP for ; 23 Oct 2012 18:17:02 -0000 Message-ID: <5086C81C.5010604@freebsd.org> Date: Tue, 23 Oct 2012 18:38:52 +0200 From: Andre Oppermann User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:16.0) Gecko/20121010 Thunderbird/16.0.1 MIME-Version: 1.0 To: Gleb Smirnoff Subject: Re: svn commit: r241931 - in head/sys: conf kern References: <201210231419.q9NEJjYH082863@svn.freebsd.org> <20121023144211.GX70741@FreeBSD.org> <5086B24C.9000606@freebsd.org> <20121023160501.GB70741@FreeBSD.org> In-Reply-To: <20121023160501.GB70741@FreeBSD.org> Content-Type: text/plain; charset=KOI8-R; format=flowed Content-Transfer-Encoding: 7bit Cc: svn-src-head@FreeBSD.org, svn-src-all@FreeBSD.org, src-committers@FreeBSD.org X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 23 Oct 2012 16:39:04 -0000 On 23.10.2012 18:05, Gleb Smirnoff wrote: > On Tue, Oct 23, 2012 at 05:05:48PM +0200, Andre Oppermann wrote: > A> There shouldn't be any users. Zero copy send is broken and > A> responsible for random kernel crashes. Zero copy receive isn't > A> supported by any modern driver. Both are useless to dangerous. > A> > A> The main problem with ZERO_COPY_SOCKETS was that it sounded great > A> and who wouldn't want to have zero copy sockets? Unfortunately > A> it doesn't work that way. > > Okay, it appeared that there are users, even on current@ mailing > list during couple of hours of exposition. > > Can we keep the old option as compatibility? No. They are not users. They simply fell for the promise of "zero copy" which it isn't. It doesn't do what the "users" believe it does. It's useless for receive and dangerous for send. I have updated NOTES and forwarded it to -current. -- Andre