Re: [Xen-devel] dom0 linux 3.6.0-rc4, crash due to ballooning althoug dom0_mem=X, max:X set

[Sander Eikelenboom <linux@xxxxxxxxxxxxxx>]

Tuesday, September 4, 2012, 8:22:41 PM, you wrote:

> On Tue, Sep 04, 2012 at 02:07:11PM -0400, Ben Guthro wrote:
>> We ran into the same issue, in newer kernels - but had not yet
>> submitted this fix.
>> 
>> One of the developers here came up with a fix (attached, and CC'ed
>> here) that fixes an issue where the p2m code reuses a structure member
>> where it shouldn't.
>> The patch adds a new "old_mfn"  member to the gnttab_map_grant_ref
>> structure, instead of re-using  dev_bus_addr.

> Wow. So that implies the m2p code had some new wonkiness in it.

> Perhaps this b9e0d95c041ca2d7ad297ee37c2e9cfab67a188f
> or
> 0930bba674e248b921ea659b036ff02564e5a5f4

> both courtesy of Stefano (who is on vacation this week :-())
> are at fault?

> Would it be possible to revert one of them (or both) and see if the
> issues disappear?

reverting b9e0d95c041ca2d7ad297ee37c2e9cfab67a188f didn't help

reverting 0930bba674e248b921ea659b036ff02564e5a5f4 didn't work out due to a lot 
of merge conflicts :S

>> 
>> 
>> If this also works for you, I can re-submit it with a Signed-off-by
>> line, if you prefer, Konrad.
>> 
>> Ben
>> 
>> 
>> On Tue, Sep 4, 2012 at 1:19 PM, Sander Eikelenboom <linux@xxxxxxxxxxxxxx> 
>> wrote:
>> >
>> > Tuesday, September 4, 2012, 6:33:47 PM, you wrote:
>> >
>> >> On Tue, Sep 04, 2012 at 06:37:57PM +0200, Sander Eikelenboom wrote:
>> >>> Hi Konrad,
>> >>>
>> >>> This seems to happen only on a intel machine i'm trying to setup as a 
>> >>> development machine (haven't seen it on my amd).
>> >>> It boots fine, i have dom0_mem=1024M,max:1024M set, the machine has 2G 
>> >>> of mem.
>> >
>> >> Is this only with Xen 4.2? As, does Xen 4.1 work?
>> >>>
>> >>> Dom0 and guest kernel are 3.6.0-rc4 with config:
>> >
>> >> If you back out:
>> >
>> >> f393387d160211f60398d58463a7e65
>> >> Author: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
>> >> Date:   Fri Aug 17 16:43:28 2012 -0400
>> >
>> >>     xen/setup: Fix one-off error when adding for-balloon PFNs to the P2M.
>> >
>> >> Do you see this bug? (Either with Xen 4.1 or Xen 4.2)?
>> >
>> > With c96aae1f7f393387d160211f60398d58463a7e65 reverted i still see this 
>> > bug (with Xen 4.2).
>> >
>> > Will use the debug patch you mailed and send back the results ...
>> >
>> >
>> >>> [*] Xen memory balloon driver
>> >>> [*]   Scrub pages before returning them to system
>> >>>
>> >>> From 
>> >>> http://wiki.xen.org/wiki/Do%EF%BB%BFm0_Memory_%E2%80%94_Where_It_Has_Not_Gone
>> >>>  , I thought this should be okay
>> >>>
>> >>> But when trying to start a PV guest with 512MB mem, the machine (dom0) 
>> >>> crashes with the stacktrace below (complete serial-log.txt attached).
>> >>>
>> >>> From the:
>> >>> "mapping kernel into physical memory
>> >>> about to get started..."
>> >>>
>> >>> I would almost say it's trying to reload dom0 ?
>> >>>
>> >>>
>> >>> [  897.161119] device vif1.0 entered promiscuous mode
>> >>> mapping kernel into physical memory
>> >>> about to get started...
>> >>> [  897.696619] xen_bridge: port 1(vif1.0) entered forwarding state
>> >>> [  897.716219] xen_bridge: port 1(vif1.0) entered forwarding state
>> >>> [  898.129465] ------------[ cut here ]------------
>> >>> [  898.132209] kernel BUG at drivers/xen/balloon.c:359!
>> >>> [  898.132209] invalid opcode: 0000 [#1] PREEMPT SMP
>> >
>> >
>> >
>> > _______________________________________________
>> > Xen-devel mailing list
>> > Xen-devel@xxxxxxxxxxxxx
>> > http://lists.xen.org/xen-devel





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