From mboxrd@z Thu Jan 1 00:00:00 1970 From: "SourceForge.net" Subject: [ kvm-Bugs-1906204 ] AMD NPT causes performance degradation Date: Mon, 03 Mar 2008 03:45:39 -0800 Message-ID: Reply-To: kvm-devel@lists.sourceforge.net Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: kvm-devel@lists.sourceforge.net Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces@lists.sourceforge.net Errors-To: kvm-devel-bounces@lists.sourceforge.net List-Id: kvm.vger.kernel.org Bugs item #1906204, was opened at 2008-03-03 13:45 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=893831&aid=1906204&group_id=180599 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: None Group: None Status: Open Resolution: None Priority: 5 Private: No Submitted By: Technologov (technologov) Assigned to: Nobody/Anonymous (nobody) Summary: AMD NPT causes performance degradation Initial Comment: Platform: F7/x64, AMD Barcelona K10, KVM-61. Guest: Windows XP SP2. By default, the new Nested Page Tables is enabled, which should accelerate guests. While it *does* accelerate guests in some areas, particularly guest OS setup time dropped by 20% - which is great, but in other areas I see performance degradation. For example: Passmark PerformanceTest v6.1 shows 2D Graphics Marks: 78.6 (without NPT) 2D Graphics Marks: 18.9 (with NPT) NPT was disabled using: # rmmod kvm-amd # modprobe kvm-amd npt=0 # dmesg | tail and all the graphics feel more sluggish, and way slower. I have used SDL rendering. -Alexey, 03.03.2008. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=893831&aid=1906204&group_id=180599 ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/