From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <200404091626.i39GQqsf002414@ccure.user-mode-linux.org> In-Reply-To: Your message of "Fri, 09 Apr 2004 14:47:32 +0200." <189201c41e30$d434cc70$2000000a@schlepptopp> References: <185d01c41e23$5996cc00$2000000a@schlepptopp> <189201c41e30$d434cc70$2000000a@schlepptopp> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii From: Jeff Dike 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: Fri, 09 Apr 2004 12:26:52 -0400 To: roland Cc: Joern Bredereck , user-mode-linux-user@lists.sourceforge.net, user-mode-linux-devel@lists.sourceforge.net, mingo@elte.hu for_spam@gmx.de said: > at least, i would be interested in getting to know: > - why this happens > - how to "tune" this, that it doesn`t happen > - if this is expected behavour on "heavy loaded systems" or probably a uml > or host-kernel bug As you said, you're making life hard for the host. My guess as to what's happening is this. You're generating a ton of IO which is pulling the host's memory into page cache. This causes UML to get swapped out because it's not doing anything except answering a ping once in a while. When it does have to answer a ping, it needs to be swapped back in, which might be hard since you're sucking down a lot of IO bandwidth. So, I don't think this says too much about whether anything's wrong with either the host or UML. Once thing you might try is do the same IO with O_DIRECT. That won't pollute the page cache. Jeff ------------------------------------------------------- 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