From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: In kvm, a single process cannot allocate more than 3.6GB ram. Why? Date: Sat, 12 Dec 2009 11:35:49 +0200 Message-ID: <4B2363F5.5020103@redhat.com> References: <4B220ADF.6030709@gmail.com> <4B235A73.9040303@redhat.com> <4B236118.6090305@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Tanel Kokk Return-path: Received: from mx1.redhat.com ([209.132.183.28]:26681 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760614AbZLLJfr (ORCPT ); Sat, 12 Dec 2009 04:35:47 -0500 In-Reply-To: <4B236118.6090305@gmail.com> Sender: kvm-owner@vger.kernel.org List-ID: On 12/12/2009 11:23 AM, Tanel Kokk wrote: > On 12/12/09 10:55, Avi Kivity wrote: > >> On 12/11/2009 11:03 AM, Tanel Kokk wrote: >> >>> Does anybody have a glue why process are not able to allocate more than >>> 3.6GB memory ? >>> >>> What should i do to allow process allocate more than 3.6GB memory? Is it >>> possible at all? >>> >>> >> A guest or host process? And what happens when you try? >> > guest process > > We discovered that if postgres process (on guest) used to use only 3.6GB > memory regardless of guest had 8GB memory in common. > > That's probably a postgres configuration error (or you're using 32-bit postgres). > Then I made simple python script, which just eat memory: > ------------------------------------ > #!/usr/bin/python > import time, random > > i = 0 > while (i< 100000000): > a[i] = random.random() > i = i + 1 > > time.sleep(600) > ------------------------------------ > And I get python MemoryError, when script has devoured about 3.6GB ram > Doesn't mean much - Python may allocate a lot more memory when extending the array. What does 'cat /proc/meminfo' in the guest say? -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.