From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.12] helo=sc8-sf-mx2.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1BF9qd-00048g-6u for user-mode-linux-devel@lists.sourceforge.net; Sun, 18 Apr 2004 03:48:27 -0700 Received: from imap.gmx.net ([213.165.64.20] helo=mail.gmx.net) by sc8-sf-mx2.sourceforge.net with smtp (Exim 4.30) id 1BF9qc-0004Bp-JO for user-mode-linux-devel@lists.sourceforge.net; Sun, 18 Apr 2004 03:48:26 -0700 Message-ID: <004801c42533$94d567b0$2000000a@schlepptopp> From: "roland" References: <185d01c41e23$5996cc00$2000000a@schlepptopp> <189201c41e30$d434cc70$2000000a@schlepptopp> <200404091626.i39GQqsf002414@ccure.user-mode-linux.org> <20040410140840.GB5782@ccure.user-mode-linux.org> <4077FDF9.7070707@upb.de> <20040410170707.GA6492@ccure.user-mode-linux.org> <224701c42280$f110e0f0$2000000a@schlepptopp> <000801c422e1$783f8030$1400a8c0@DAVIDVAIO> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Subject: [uml-devel] Re: [uml-user] Network lags Sender: user-mode-linux-devel-admin@lists.sourceforge.net Errors-To: user-mode-linux-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: The user-mode Linux development list List-Post: List-Help: List-Subscribe: , List-Archive: Date: Sun, 18 Apr 2004 12:54:53 +0200 To: user-mode-linux-user@lists.sourceforge.net, Matthew Bloch Cc: user-mode-linux-devel@lists.sourceforge.net hey, when the mlock patch doesn`t go into uml officially - why not updating it to the latest 2.4.x and 2.6.x uml and uploading it to the sourceforge patch section at http://sourceforge.net/tracker/?group_id=429&atid=300429 and "maintaining" it there? so others could find it, download it, use it, give comments...... regards roland ----- Original Message ----- From: "Matthew Bloch" To: Cc: Sent: Friday, April 16, 2004 5:12 PM Subject: Re: [uml-user] Network lags > David Cannings wrote: > >>>Anyone else who's running lots of UMLs with interactive sessions may have > >>>noticed the following symptoms which this patch cures: > >>> > >>> * irregular ping times to UMLs-- huge delay for the first ping, a few > >>> normal, a couple of long delays etc.; > > > > The huge delay is often related to ARP, a fundamental part of 802.3/true > > ethernet. > > Indeed, but when logging back on to an ssh session etc. it's very > irritating for customers to find their machine takes seconds to "wake > up" while the 2.4 kernel swaps stuff back in. > > [snip] > > The problem with "just activating that option" is that many people will do > > it blindly, unaware of the serious implications it could have to their host. > > Whilst mlocking an area of memory may not affect you now, or in the next ten > > minutes, it could cause trouble in three weeks when you start doing > > something on the host that is memory intensive. In the last three years of > > running a remote server I have only had to turn up on site to fix it twice. > > Both were very silly things, one that I'd "just activated" to see what it > > would do. It cost me a rather expensive journey half way across the country > > to fix. > > Since writing that post back in October, we've deployed the mlock patch > across two rackfuls of hosts, and we've never had a host kernel "just > crash" (well we have, but that was down to something else ): longest > uptime on one group of our hosts is 100 days. Yes it was experimental > but we did a bit of testing first. > > From this experience; I would disagree that using lots of mlocked > memory inherently destabilises the machine. I'm sure it *can* but this > goes for a lot of things. > > [snip] > > The idea behind UML is to create a separate environment from the host, > > constructing a UML kernel that can interfere so badly with the host is the > > total opposite. > > It's very easy for a UML kernel to trash the host, and I'm not sure > anyone knows what "the idea behind UML" is :-) > > I can see Jeff's point about the mlock patch despite the fact that it > solved a major problem for us with deploying UML in a hosting > environment. Jeff's proposed new memory management features will give > us more flexibility than my simple on/off mlock patch, and allows him to > wash his hands of these grubby management decisions. > > cheerio, > > -- > Matthew Bloch Bytemark Hosting > http://www.bytemark-hosting.co.uk/ > phone UK: 0845 004 3 004 US: 1-877 BYTEMAR > Dedicated Linux hosts from 15ukp ($26) per month > > > > ------------------------------------------------------- > This SF.Net email is sponsored by: IBM Linux Tutorials > Free Linux tutorial presented by Daniel Robbins, President and CEO of > GenToo technologies. Learn everything from fundamentals to system > administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click > _______________________________________________ > User-mode-linux-user mailing list > User-mode-linux-user@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user > ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel