From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list1-new.sourceforge.net with esmtp (Exim 4.43) id 1Gmfsq-0005N9-Q6 for user-mode-linux-devel@lists.sourceforge.net; Tue, 21 Nov 2006 16:22:36 -0800 Received: from smtp008.mail.ukl.yahoo.com ([217.12.11.62]) by mail.sourceforge.net with smtp (Exim 4.44) id 1Gmfso-0002R6-Rz for user-mode-linux-devel@lists.sourceforge.net; Tue, 21 Nov 2006 16:22:36 -0800 From: Blaisorblade Date: Wed, 22 Nov 2006 01:22:24 +0100 References: <22a33e9f0611180345w7ec64513l34424a59e1671479@mail.gmail.com> <200611210813.14745.blaisorblade@yahoo.it> <22a33e9f0611211123w3b57d6bdh5e599a87589816c9@mail.gmail.com> In-Reply-To: <22a33e9f0611211123w3b57d6bdh5e599a87589816c9@mail.gmail.com> MIME-Version: 1.0 Content-Disposition: inline Message-Id: <200611220122.24515.blaisorblade@yahoo.it> Subject: Re: [uml-devel] Problem with newer (>2.6.14) UML kernels hanging under Xen DomU/Centos 4.4 List-Id: The user-mode Linux development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: user-mode-linux-devel-bounces@lists.sourceforge.net Errors-To: user-mode-linux-devel-bounces@lists.sourceforge.net To: Matt Willsher Cc: user-mode-linux-devel@lists.sourceforge.net On Tuesday 21 November 2006 20:23, Matt Willsher wrote: > On 11/21/06, Blaisorblade wrote: > > On Saturday 18 November 2006 12:45, Matt Willsher wrote: > > > I've been trying to get UML running under a Xen DomU running Centos > > > 4.4, which I understand is a reasonable thing to do. > > > > > > When I started out I was using a download 2.6.12 kernel and the image > > > booted up fine. I then tried 2.6.18.2, which is hanging after VFS: > > > Mounted root (ext3 filesystem) readonly. I've had someone check my > > > kernel and the image on another machine and it works without problem. > > > I've tried some other kernels, and 2.6.14 seemed ok, 2.6.16 wasn't. > > > > I have two suggestions for you to try: > > * reduce CONFIG_HOST_VM_SPLIT for UML guest kernels (Xen consumes part of > > the available memory for UML, which causes crashes) > > > > * try if booting with mode=tt helps - around 2.6.14 or 2.6.15 skas0 > > support was introduced (a very big change!) and become the new default, > > so that's the 1st likely culprit. > > Thank you for your suggestions. > > I must correct myself. 2.6.14 does indeed hang in the same way as > later kernels. I think I tried 2.6.13 resulting in the same hang but I > can't be sure (I've tried rather a lot of kernels this last week!) > > I've applied your latest patch bundle to the 2.6.18.3 tree, and set > the VM_HOST split to 1/3. Booting with this, the guest kernel hangs at > the same point. With mode=tt it crashes outright. mode=tt can possibly work only on _old_ kernel, say the first one where skas0 was introduced i.e. (if my guess is right) the first one breaking under Xen. > I've posted the > output from the run below. I've also got an strace output, which I can > post if you want, but thought I'd check first as it's 380K. The output makes me suspicious of some misconfiguration - I've never seen a bug giving a misleading "no init found". And it happens that even smart users use different command lines, say, because they use a script for the default kernel and do not use it for the other one. /home/uml/.uml ($HOME/.uml) seems not writable according to messages below, which is _very_ strange. If the error message is wrong it should be checked in strace output, looking for EPERM or EACCESS on access to files mentioned below I guess (but I'll not have the time to even give a look to it, maybe someone else will be able or you can give a look yourself). > The same command line used on the below works with a 2.6.12.2-bb11 > kernel. I've also tried init=/bin/sh, again with the same results as > below. > > Checking that ptrace can change system call numbers...OK > Checking syscall emulation patch for ptrace...OK > Checking advanced syscall emulation patch for ptrace...OK > Checking for tmpfs mount on /dev/shm...OK > Checking PROT_EXEC mmap in /dev/shm/...OK > UML running in TT mode > tracing thread pid = 1350 > Checking that ptrace can change system call numbers...OK > Checking syscall emulation patch for ptrace...OK > Checking advanced syscall emulation patch for ptrace...OK > Linux version 2.6.18.3-bb2 (root@localhost) (gcc version 3.4.6 > 20060404 (Red Hat 3.4.6-3)) #3 Tue Nov 21 19:06:28 GMT 2006 > Built 1 zonelists. Total pages: 16384 > Kernel command line: ubd0=/home/uml/images/ano_router_root_fs > ubd1=/home/uml/images/ano_router_swap_fs mode=tt mem=64M con=null > con0=fd:0,fd:1 con1=port:9000 eth0=tuntap,umltun0 eth1=tuntap,umltun1 > root=98:0 > PID hash table entries: 512 (order: 9, 2048 bytes) > Dentry cache hash table entries: 8192 (order: 3, 32768 bytes) > Inode-cache hash table entries: 4096 (order: 2, 16384 bytes) > Memory: 61164k available > Mount-cache hash table entries: 512 > Checking for host processor cmov support...Yes > Checking for host processor xmm support...No > Checking that host ptys support output SIGIO...Yes > Checking that host ptys support SIGIO on close...No, enabling workaround > /usr/include/linux/aio_abi.h not present during build > 2.6 host AIO support not used - falling back to I/O thread > Failed to initialize umid "anoroute", trying with a random umid > make_umid - mkstemp(/home/uml/.uml/MyLtrF) failed: Permission denied > NET: Registered protocol family 16 > NET: Registered protocol family 2 > IP route cache hash table entries: 512 (order: -1, 2048 bytes) > TCP established hash table entries: 2048 (order: 1, 8192 bytes) > TCP bind hash table entries: 1024 (order: 0, 4096 bytes) > TCP: Hash tables configured (established 2048 bind 1024) > TCP reno registered > Checking host MADV_REMOVE support...OK > make_umid - mkstemp(/home/uml/.uml/i5cVhQ) failed: Permission denied > ubd: Synchronous mode > Netdevice 0 : TUN/TAP backend - > Netdevice 1 : TUN/TAP backend - > Host TLS support detected > Detected host type: i386 > Initializing Cryptographic API > io scheduler noop registered > io scheduler anticipatory registered > io scheduler deadline registered > io scheduler cfq registered (default) > NET: Registered protocol family 1 > NET: Registered protocol family 17 > Initialized stdio console driver > Console initialized on /dev/tty0 > Initializing software serial port version 1 > ubda: unknown partition table > ubdb: unknown partition table > kjournald starting. Commit interval 5 seconds > EXT3-fs: mounted filesystem with ordered data mode. > VFS: Mounted root (ext3 filesystem) readonly. > Kernel panic - not syncing: No init found. Try passing init= option to > kernel. -- Inform me of my mistakes, so I can add them to my list! Paolo Giarrusso, aka Blaisorblade http://www.user-mode-linux.org/~blaisorblade Chiacchiera con i tuoi amici in tempo reale! http://it.yahoo.com/mail_it/foot/*http://it.messenger.yahoo.com ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel