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 1CPrIn-0005tu-3g for user-mode-linux-devel@lists.sourceforge.net; Thu, 04 Nov 2004 15:46:01 -0800 Received: from smtp004.mail.ukl.yahoo.com ([217.12.11.35]) by sc8-sf-mx2.sourceforge.net with smtp (Exim 4.41) id 1CPrIl-0006kM-1T for user-mode-linux-devel@lists.sourceforge.net; Thu, 04 Nov 2004 15:46:00 -0800 From: Blaisorblade Subject: Re: [uml-devel] Fighting latency References: <20041104155015.GA29182@gandalf.intern.marcant.net> In-Reply-To: <20041104155015.GA29182@gandalf.intern.marcant.net> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200411050044.59629.blaisorblade_spam@yahoo.it> 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, 5 Nov 2004 00:44:59 +0100 To: user-mode-linux-devel@lists.sourceforge.net Cc: nils toedtmann On Thursday 04 November 2004 16:50, nils toedtmann wrote: > Moin, > > in some UMLs i run services which do not like latency, eg. VoIP- and > gameserver. I previously observed my UMLs going into meditation for a split > second every few seconds, but that bucking almost disappeard by taking the > usual tuning steps (SKAS, sysemu, $TMP on tmpfs). Nevertheless, my UMLs are > still not as responsive as i would like them to. It's not a matter of CPU > or network performance. Host and guest are >=95% idle all the time, > bandwidth use is far from my UML-bench- marks. > > I tried to renice the UML processes, but seems not to help (it's hard to > measure, just the "feeling" while listening to audio or onlinegaming). > > Any suggestions? > > I enabled "PREEMPT" in host kernel. Maybe that's a bad idea? This problem is an old one. Search the archives for "odd ping problems", which is about long ping delay. A fix was proposed a while ago, which consisted in mlock()ing the memory. But Jeff Dike refused it because he said "I want to write a much more complex and more optimal solution. Mlock() is an hack". Even so, I'll try to update the patch, fix it on the security side (that one required setuid()'ing UML, which is purposeless) and push it for inclusion, if possible. Bye -- Paolo Giarrusso, aka Blaisorblade Linux registered user n. 292729 ------------------------------------------------------- This SF.Net email is sponsored by: Sybase ASE Linux Express Edition - download now for FREE LinuxWorld Reader's Choice Award Winner for best database on Linux. http://ads.osdn.com/?ad_id=5588&alloc_id=12065&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