WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

Re: [Xen-devel] rootfs as RAMDisk + Hypervisor: Cannot allocate memory

To: Jan Beulich <JBeulich@xxxxxxxxxx>
Subject: Re: [Xen-devel] rootfs as RAMDisk + Hypervisor: Cannot allocate memory
From: Robyn Bachofer <r.bachofer@xxxxxxxxxxxxxx>
Date: Fri, 8 Oct 2010 09:38:32 +0200
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Fri, 08 Oct 2010 00:39:24 -0700
Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:cc:content-type; bh=j4CjCRsbUWcc2HzfU1z8XlmncUSMKXKRI4Np3PUiMdI=; b=vlr0SLdn4bUhlTaBgQGoeP81KcYQ41JtDLue2tB1dzCDxTYf+SRnadgAdIwdXgWw8C h9L81sECFnHTzmwO31/7o9+DnvMYMGtTVSUWWHnTRLNuSDp/EihE4QfykfC+MKmnp0+O mYqbENhA9c8zF6j0YvksYsmEBASQ2M14UvEkg=
Domainkey-signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=ngPGopDXoKXQkjqdE6vX+U9Z+k/53VehqXNAz2nbjg6N5y+r1I2QOgaeZgTzqS8ld5 ZIyppdg67VLjL+VrmxVSFQ60jy5zRtw/v0k9tpf+Fcj4KFVra7PaXYHrvst8IuwmjucS peEQVCMX3Cq503uGCMJXtApS3gQsrNIighD30=
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <4CADDB9A020000780001B3F3@xxxxxxxxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <AANLkTi=rKVgrj9QNr8-0iTAK-jFf=NCDNSRDbGAcMR7Z@xxxxxxxxxxxxxx> <4CADDB9A020000780001B3F3@xxxxxxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Hello Jan,

that's a good guess.
I found your pasted line in mm/vmalloc.c, line 108.
What can i do? A workaround is to change from ramdisk to nfs, but this is not fine.
Or a way to "fix" this problem?

Robyn


2010/10/7 Jan Beulich <JBeulich@xxxxxxxxxx>
>>> On 07.10.10 at 13:21, Robyn Bachofer <r.bachofer@xxxxxxxxxxxxxx> wrote:
> [hostname ~]# modprobe iscsi_tcp
> Warning: at mm/vmalloc.c:108 vmap_page_range_noflush+0x22/0x2e2()
> Hardware name: IBM eServer BladeCenter HS21 -[7995A1G]-
> Pid: 2344, comm: modprobe Tainted: C       W 2.6.32.23-pvops #2
> Call Trace:
> [<ffffffffxxxxxxxx>] ? warn_slowpath_common
> [<ffffffffxxxxxxxx>] ? vmap_page_range_noflush
> [<ffffffffxxxxxxxx>] ? map_vm_area
> [<ffffffffxxxxxxxx>] ? __vmalloc_area_node
> [<ffffffffxxxxxxxx>] ? load_module
> [<ffffffffxxxxxxxx>] ? do_page_fault
> [<ffffffffxxxxxxxx>] ? sys_init_module
> [<ffffffffxxxxxxxx>] ? sys_call_fastpath
> ---[ end trace xxxxxxxx ]---
> FATAL: Error inserting iscsi_tcp
> (/lib/modules/2.6.32.23-pvops/kernel/driver/scsi/iscsi_tcp.ko): Cannot
> allocate memory

Can you match this to a source line? Namely, if it maps to

               if (WARN_ON(!pte_none(*pte)))

in vmap_pte_range(), it would suggest there's some page table
cleanup missing after the initrd is no longer needed at its original
location (with the sizes you provided its quite certain that it runs
into the virtual address range used for modules). For native,
there's no mapping of the initrd following the kernel image (and
honestly I don't know why Xen specifies it as being mapped
there - if you had one of about 2G in size, Xen would refuse to
load your Dom0 altogether; perhaps time for another ELF note
indicating that the kernel can do without the initrd being
mapped into virtual space), so Xen kernels need to clean up
the left over page table entries, and apparently the pv-ops
code didn't inherit the respective XenoLinux bits.

Jan




--
Robyn Bachofer

Pearl-S.-Buck-Str. 12
D-73037 Göppingen
Telefon: +49 (0) 7161 4018708
Mobil: +49 (0) 176 49230082
E-Mail: r.bachofer@xxxxxxxxxxxxxx
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel