From owner-freebsd-questions@FreeBSD.ORG Mon Apr 24 10:19:37 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1457F16A402 for ; Mon, 24 Apr 2006 10:19:37 +0000 (UTC) (envelope-from tedm@toybox.placo.com) Received: from mail.freebsd-corp-net-guide.com (mail.web-strider.com [65.75.192.90]) by mx1.FreeBSD.org (Postfix) with ESMTP id 82C4243D45 for ; Mon, 24 Apr 2006 10:19:36 +0000 (GMT) (envelope-from tedm@toybox.placo.com) Received: from tedwin2k (nat-rtr.freebsd-corp-net-guide.com [65.75.197.130]) by mail.freebsd-corp-net-guide.com (8.11.1/8.11.1) with SMTP id k3OAJPu43077; Mon, 24 Apr 2006 03:19:25 -0700 (PDT) (envelope-from tedm@toybox.placo.com) From: "Ted Mittelstaedt" To: "Chuck Swiger" Date: Mon, 24 Apr 2006 03:19:25 -0700 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.6604 (9.0.2911.0) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1506 In-Reply-To: <444AEB7E.1030406@mac.com> Importance: Normal Cc: freebsd-questions Subject: RE: anyone understand torvald's critique of freebsd? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 24 Apr 2006 10:19:37 -0000 >-----Original Message----- >From: Chuck Swiger [mailto:cswiger@mac.com] >Sent: Saturday, April 22, 2006 7:51 PM >To: Ted Mittelstaedt >Cc: freebsd-questions >Subject: Re: anyone understand torvald's critique of freebsd? > > >Ted Mittelstaedt wrote: >> Then why does Linus think manipulating the VM page table mappings >> is bad? That is, why does he -really- think it's bad, not the >> publically-given reason? Is it because Linux is extrordinairly >> inefficient in page table mappings due to some structural decision >> that Linus made that cannot be reversed now, that it could never >> be any good at it? Or is there some other reason? > >I can't speak with certainty as to what someone else might >think; no doubt Linus >is entirely capable of explaining his own position should you >wish to inquire, The guy is bitching about an option that's not even turned on, thus it's not a legitimate criticism - there's an ulterior motive somewhere. He isn't going to explain this of course - if he was being honest he never would have bitched about it in the first place. >however.... :-) > >I think Linus doesn't care much for Zero-copy sockets because >for the common >case of 1500/1504-byte MTU, you end up wasting at least 60% of >a 4096-byte page >for each packet, and maybe ?three? times that much if your >hardware splits the >packet into separate pages for the mbuf header, the packet >headers, and the >packet data. > ram is cheap these days. I've seen things before that are a lot faster to do the memory-hogging way. If this is one of these then the ram usage shouldn't be an issue. Ted