From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andre Przywara Subject: Re: 2.6.35-rc1 regression with pvclock and smp guests Date: Tue, 27 Jul 2010 13:49:37 +0200 Message-ID: <4C4EC7D1.6030708@amd.com> References: <4C483F67.1010007@amd.com> <4C4BF96B.7010005@redhat.com> <4C4D4B8B.80006@amd.com> <4C4EAEFC.20207@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Cc: "glommer@redhat.com" , Zachary Amsden , KVM list To: Avi Kivity Return-path: Received: from tx2ehsobe004.messaging.microsoft.com ([65.55.88.14]:3254 "EHLO TX2EHSOBE008.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752291Ab0G0Lwi (ORCPT ); Tue, 27 Jul 2010 07:52:38 -0400 In-Reply-To: <4C4EAEFC.20207@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Avi Kivity wrote: > On 07/26/2010 11:47 AM, Andre Przywara wrote: >>> Does this go away with CONFIG_DEBUG_RODATA=n? If so, it's a known >>> bug in the atomic_*() clobber lists. >>> >> Unfortunately the bug persists even with CONFIG_DEBUG_RODATA disabled. >> The debug options I had enabled now are: >> CONFIG_DEBUG_DEVRES=y >> CONFIG_DEBUG_FS=y >> CONFIG_DEBUG_KERNEL=y >> CONFIG_DEBUG_BUGVERBOSE=y >> CONFIG_DEBUG_MEMORY_INIT=y >> CONFIG_DEBUG_STACKOVERFLOW=y >> CONFIG_DEBUG_BOOT_PARAMS=y >> >> I even disabled all kernel debug options, that does not help, too. >> > > Does changing last_value in arch/x86/kernel/pvclock.c to be non-static help? No, no change. It still hangs. > What is the guest executing when it hangs? Both VCPUs are halted, the monitor and System.map tell me it's in native_safe_halt(). The code sequence confirms this, it is an intentional sti;hlt condition. Using -smp 16 also shows that all 16 VCPUs are stuck. Regards, Andre. -- Andre Przywara AMD-Operating System Research Center (OSRC), Dresden, Germany Tel: +49 351 448-3567-12