From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MUQYU-0006uj-GU for qemu-devel@nongnu.org; Fri, 24 Jul 2009 15:35:46 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MUQYO-0006tc-VF for qemu-devel@nongnu.org; Fri, 24 Jul 2009 15:35:45 -0400 Received: from [199.232.76.173] (port=51939 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MUQYO-0006tV-Oi for qemu-devel@nongnu.org; Fri, 24 Jul 2009 15:35:40 -0400 Received: from mx2.redhat.com ([66.187.237.31]:47622) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1MUQYO-0003mF-72 for qemu-devel@nongnu.org; Fri, 24 Jul 2009 15:35:40 -0400 Date: Fri, 24 Jul 2009 16:42:35 -0300 From: Glauber Costa Subject: Re: [Qemu-devel] Re: kvm: savevm is broken for me Message-ID: <20090724194235.GA19431@poweredge.glommer> References: <20090723185844.474f7c62@doriath> <20090724105402.1ea81ad5@doriath> <20090724112053.62b67d03@doriath> <60E5AA22-8B6F-488A-BD95-FA3B28935D23@suse.de> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="YZ5djTAD1cGYuMQK" Content-Disposition: inline In-Reply-To: <60E5AA22-8B6F-488A-BD95-FA3B28935D23@suse.de> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: aliguori@us.ibm.com, qemu-devel@nongnu.org, Luiz Capitulino --YZ5djTAD1cGYuMQK Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, Jul 24, 2009 at 04:27:38PM +0200, Alexander Graf wrote: > > On 24.07.2009, at 16:20, Luiz Capitulino wrote: > >> On Fri, 24 Jul 2009 16:18:02 +0200 >> Alexander Graf wrote: >> >>> >>> On 24.07.2009, at 15:54, Luiz Capitulino wrote: >>> >>>> On Fri, 24 Jul 2009 00:06:13 +0200 >>>> Alexander Graf wrote: >>>> >>>>> On 23.07.2009, at 23:58, Luiz Capitulino wrote: >>>>> >>>>>> >>>>>> Hi there, >>>>>> >>>>>> If I try to 'savevm' with latest Anthony's tree (HEAD >>>>>> 6f725c139ae975646c44ace77bf796318a5783da) QEMU will hang and I >>>>>> know >>>>>> it's not saving anything because vmstat shows no disk activity >>>>>> (which >>>>>> is the opposite behavior of when 'savevm' works). >>>>>> >>>>>> According to 'git bisect' the week's winner is: >>>>>> >>>>>> """ >>>>>> commit bd8367761236cd5c435598aeb2f1b8240c09b059 >>>>>> Author: Alexander Graf >>>>>> Date: Fri Jul 17 13:51:48 2009 +0200 >>>>>> >>>>>> Fake dirty loggin when it's not there >>>>>> """ >>>>>> >>>>>> Indeed, reverting this makes 'savevm' work for me. >>>>> >>>>> >>>>> Yikes. I have no idea why, but just revert the patch :-). I don't >>>>> really need it anymore since we now have dirty logging in PPC. >>>>> >>>>> Maybe it's the if (is dirty logging really enabled?) in the >>>>> beginning? >>>> >>>> Yes, it's the if. I have removed it and savevm works. >>>> >>>> Can you submit the fix please? >>> >>> Eh - what fix? You found that something doesn't set or evaluate the >>> flags right. That still doesn't tell us who behaves incorrectly. >> >> Ah, okay. I thought you meant the 'if' _was_ the bug. >> >> Better to revert then? > > Even better yet to find out who's doing something wrong :-). It's actually quite simple. you continue'd instead of break'ing during the dirty log loop, which would put us in an infinite loop Patch follows: --YZ5djTAD1cGYuMQK Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="0001-remove-infinite-loop-for-migration.patch" >>From d249467b75dea5fad2c305d88edd447e8745494f Mon Sep 17 00:00:00 2001 From: Glauber Costa Date: Fri, 24 Jul 2009 15:32:46 -0400 Subject: [PATCH] remove infinite loop for migration Linux is so good, that it can finish an endless loop in 5 seconds. Unfortunately, not everybody uses Linux, and while kvm is still linux-only, this is likely to change. So remove an endless loop in migration code recently introduced. Signed-off-by: Glauber Costa --- kvm-all.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/kvm-all.c b/kvm-all.c index 824bb4c..b8b9539 100644 --- a/kvm-all.c +++ b/kvm-all.c @@ -333,7 +333,7 @@ int kvm_physical_sync_dirty_bitmap(target_phys_addr_t start_addr, /* We didn't activate dirty logging? Don't care then. */ if(!(mem->flags & KVM_MEM_LOG_DIRTY_PAGES)) { - continue; + break; } size = ((mem->memory_size >> TARGET_PAGE_BITS) + 7) / 8; -- 1.6.2.2 --YZ5djTAD1cGYuMQK--