From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Fjellstrom Subject: Re: How many threads should a kvm vm be starting? Date: Tue, 27 Sep 2011 16:04:41 -0600 Message-ID: <201109271604.41502.thomas@fjellstrom.ca> References: <201109261829.38937.thomas@fjellstrom.ca> <4E816E27.8040005@redhat.com> Reply-To: thomas@fjellstrom.ca Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Avi Kivity Return-path: Received: from mail.tomasu.net ([64.85.170.232]:33599 "EHLO mail.tomasu.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751572Ab1I0WEu (ORCPT ); Tue, 27 Sep 2011 18:04:50 -0400 In-Reply-To: <4E816E27.8040005@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On September 27, 2011, Avi Kivity wrote: > On 09/27/2011 03:29 AM, Thomas Fjellstrom wrote: > > I just noticed something interesting, a virtual machine on one of my > > servers seems to have 69 threads (including the main thread). Other > > guests on the machine only have a couple threads. > > > > Is this normal? or has something gone horribly wrong? > > It's normal if the guest does a lot of I/O. The thread count should go > down when the guest idles. Ah, that would make sense. Though it kind of defeats assigning a vm a single cpu/core. A single VM can now DOS an entire multi-core-cpu server. It pretty much pegged my dual core (with HT) server for a couple hours. -- Thomas Fjellstrom thomas@fjellstrom.ca