From mboxrd@z Thu Jan 1 00:00:00 1970 From: Srivatsa Vaddagiri Subject: Re: [PATCH] kvm-vmx: add module parameter to avoid trapping HLT instructions (v2) Date: Fri, 3 Dec 2010 16:42:52 +0530 Message-ID: <20101203111252.GB27994@linux.vnet.ibm.com> References: <1291298357-5695-1-git-send-email-aliguori@us.ibm.com> <4CF7B9FF.9000904@codemonkey.ws> <4CF8BA99.9070002@redhat.com> Reply-To: vatsa@linux.vnet.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Anthony Liguori , lidong chen , kvm@vger.kernel.org, Marcelo Tosatti , Chris Wright To: Avi Kivity Return-path: Received: from e38.co.us.ibm.com ([32.97.110.159]:38291 "EHLO e38.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932346Ab0LCLM6 (ORCPT ); Fri, 3 Dec 2010 06:12:58 -0500 Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by e38.co.us.ibm.com (8.14.4/8.13.1) with ESMTP id oB3C4XLD017751 for ; Fri, 3 Dec 2010 05:04:33 -0700 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay04.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id oB3BCv26136482 for ; Fri, 3 Dec 2010 04:12:57 -0700 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id oB3BCukt012144 for ; Fri, 3 Dec 2010 04:12:56 -0700 Content-Disposition: inline In-Reply-To: <4CF8BA99.9070002@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Fri, Dec 03, 2010 at 11:38:33AM +0200, Avi Kivity wrote: > What if one of the guest crashes qemu or invokes a powerdown? > Suddenly the others get 33% each (with 1% going to my secret > round-up account). Doesn't seem like a reliable way to limit cpu. Some monitoring tool will need to catch that event and spawn a "dummy" VM to consume 25% cpu, bringing back everyone's use to 25% as before. That's admittedly not neat, but that's what we are thinking of atm in absence of a better solution to the problem (ex: kernel scheduler supporting hard-limits). - vatsa