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 1CQJkv-0003n6-2Q for user-mode-linux-devel@lists.sourceforge.net; Fri, 05 Nov 2004 22:08:57 -0800 Received: from adsl-b5-232-218.telepac.pt ([82.154.232.218] helo=puma-vgertech.no-ip.com) by sc8-sf-mx2.sourceforge.net with esmtp (Exim 4.41) id 1CQJkt-0000LG-Cs for user-mode-linux-devel@lists.sourceforge.net; Fri, 05 Nov 2004 22:08:56 -0800 Message-ID: <418C6A72.4080807@vgertech.com> From: Nuno Silva MIME-Version: 1.0 Subject: Re: [uml-devel] Fighting latency References: <20041104155015.GA29182@gandalf.intern.marcant.net> <200411050044.59629.blaisorblade_spam@yahoo.it> <418AEB71.1090005@vgertech.com> <200411052038.15491.blaisorblade_spam@yahoo.it> In-Reply-To: <200411052038.15491.blaisorblade_spam@yahoo.it> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit 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: Sat, 06 Nov 2004 06:08:50 +0000 To: Blaisorblade Cc: user-mode-linux-devel@lists.sourceforge.net, nils toedtmann Blaisorblade wrote: >>Maybe having the linux binary in a ramfs will work better? > > Wise idea! But you forgot the UML "RAM" from $TMPDIR. No i didn't :-) And i advise against it because of the problems that you point out below (OOM). Anyway, if the data is frequently used it won't be sent to swap... If you only touch that data once every 5 minutes and you have some memory pressure you may get a bigger latency. If you must have fast-as-it-gets memory access making several UBDs, one of them very small in ramfs, may be better, YMMV. ... >>You can also do some creative mount --bind, to mount only one ramfs >>instance, if you have many UMLs running. > > Not needed I think - use different names for UML binaries as needed. It will > pickup a good name for the RAM file. I was thinking about chroot environments. And saving some MB by using the same binary - living in ramfs - to run many UMLs. Regarding double-cacheing you may try NFS or directIO (with directIO the guest can create disk I/O even if it's not needed and ruin the host's I/O performance). Again, YMMV. Thanks, Nuno Silva ------------------------------------------------------- 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