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* kernel log flooded with: xen_balloon: reserve_additional_memory: add_memory() failed: -17
@ 2012-12-19  8:47 James Dingwall
  2012-12-19 10:55 ` James Dingwall
                   ` (2 more replies)
  0 siblings, 3 replies; 14+ messages in thread
From: James Dingwall @ 2012-12-19  8:47 UTC (permalink / raw)
  To: xen-devel

Hi,

I have encountered an apparently benign error on two systems where the 
dom0 kernel log is flooded with messages like:

[52482.163855] System RAM resource [mem 0x1b8000000-0x1bfffffff] cannot 
be added
[52482.163860] xen_balloon: reserve_additional_memory: add_memory() 
failed: -17

The first line is from drivers/xen/xen-balloon.c, the second from 
mm/memory_hotplug.c

The trigger for the messages seems to be the first occasion that a Xen 
guest is shutdown.  I have noted this in a vanilla 3.6.7 and kernel 
3.5.0-18 built from Ubuntu sources.  Xen version is 4.2.0.  It is not 
clear why the dom0 is kernel is trying to balloon up as the Xen command 
line is specifies a fixed dom0 memory allocation and noselfballooning is 
specified for the kernel and ballooning is also disabled in the 
xend-config.sxp / xl.conf (one system using xm, another xl)

xen command line:
placeholder xsave=0 iommu=0 console=vga,com2 com2=115200,8n1 
dom0_mem=max:6144m

kernel command line:
root=/dev/loop0 ro console=tty1 console=hvc0 earlyprintk=xen nomodeset 
noselfballooning

Examining /proc/iomem does show that the dom0 memory allocation is 
actually 64kb short of 6144Mb:

cat /proc/iomem | grep System\ RAM
00010000-0009bfff : System RAM      [573440 bytes]
00100000-cb2dffff : System RAM      [3407740928 bytes]
100000000-1b4d83fff : System RAM    [3034071040 bytes]

Total system ram: 6442385408 - 6x2^30 = 65536

The memory range indicated in the log message is "Unusable memory" in 
/proc/iomem:
1b4d84000-82fffffff : Unusable memory

Another point of interest is that we have multiple "identical" hardware 
platforms (Dell T320) for the system running the 3.5.0-18 kernel but 
only see this error on a slightly more recent system.  Older systems 
show in /proc/iomem that all memory is System RAM.

100000000-82fffffff : System RAM  [older system BIOS 1.0]

100000000-1b4d83fff : System RAM  [newer system BIOS 1.3]
1b4d84000-82fffffff : Unusable memory

The BIOS revision between the old and new has changed so I was 
wondering if it is possible that there is a white list which affects the 
impact of the kernel option:
CONFIG_X86_RESERVE_LOW=64
This is only a guess since the amount of memory reserved is equivalent 
to the short fall calculated above.  If this is the right area perhaps 
the dom0 calculation for its memory entitlement needs to be taught to 
not to try and hotplug the missing 64k when it has been reserved.

If any other information would be useful then please let me know.

Thanks,
James

^ permalink raw reply	[flat|nested] 14+ messages in thread
* Re: kernel log flooded with: xen_balloon: reserve_additional_memory: add_memory() failed: -17
@ 2012-12-24 14:39 Daniel Kiper
  2013-01-24 21:38 ` Carsten Schiers
  0 siblings, 1 reply; 14+ messages in thread
From: Daniel Kiper @ 2012-12-24 14:39 UTC (permalink / raw)
  To: carsten; +Cc: xen-devel, james-xen, konrad.wilk

Hi,

> I had the same messages flooding logs, but it was in DomUs. It came together with e.g.:
>
>     System RAM resource [mem 0x20000000-0x3fffffff] cannot be added
>
> I am not 100% sure, but it was only for DomUs with PCI and PCIe devices passed-through.
>
> Xen 4.2.1, Dom0&DomU Kernel 3.7.1. Xen commandline with dom0_mem=2G and dom0_mem=2G,max:2G.
> Machine is an Intel 64 Bit 16 GB installation.
>
> Difficult to check deeper, as it made me so nervous that I reverted to Xen 4.1, but I could
> certainly re-install it after Xmas, if it is helping...

Thanks for update. I fill that it could be linked with
recent balloon driver updates. I will take a look at that
bug in new year.

Daniel

^ permalink raw reply	[flat|nested] 14+ messages in thread
* Re: kernel log flooded with: xen_balloon: reserve_additional_memory: add_memory() failed: -17
@ 2013-01-25 10:48 Daniel Kiper
  2013-01-28 16:36 ` Darren Shepherd
  0 siblings, 1 reply; 14+ messages in thread
From: Daniel Kiper @ 2013-01-25 10:48 UTC (permalink / raw)
  To: carsten; +Cc: xen-devel, james-xen, konrad.wilk

Hi Carsten,

> have you already had a chance to look at the issue?

Sadly not yet because I am working on my lab upgrade
which is needed for this work too. However, I will take
a look at this ASAP. Stay tuned.

Daniel

^ permalink raw reply	[flat|nested] 14+ messages in thread
* Re: kernel log flooded with: xen_balloon: reserve_additional_memory: add_memory() failed: -17
@ 2013-01-29 11:53 Daniel Kiper
  0 siblings, 0 replies; 14+ messages in thread
From: Daniel Kiper @ 2013-01-29 11:53 UTC (permalink / raw)
  To: darren.s.shepherd; +Cc: carsten, james-xen, xen-devel

Hi,

> biting this behavior.  The specific
> error I'm seeing is
>
> xen_balloon: reserve_additional_memory: add_memory() failed: -17
> System RAM resource 88000000 - 8fffffff cannot be added
>
> This is a lab system that I'm actively working on so I can give
> whatever info you need or run whatever.  Below is the xl info and xl
> dmesg output

[...]

Thanks. I am going to work on this about the
middle of February after my holiday.

Daniel

^ permalink raw reply	[flat|nested] 14+ messages in thread
end of thread, other threads:[~2013-01-29 11:53 UTC | newest]

Thread overview: 14+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-12-19  8:47 kernel log flooded with: xen_balloon: reserve_additional_memory: add_memory() failed: -17 James Dingwall
2012-12-19 10:55 ` James Dingwall
2012-12-21 20:23   ` Konrad Rzeszutek Wilk
2013-01-02 10:28     ` James Dingwall
2012-12-20 14:50 ` Jacek Konieczny
2012-12-20 15:55   ` James Dingwall
2012-12-21 20:25 ` Konrad Rzeszutek Wilk
2012-12-23 10:41   ` Carsten Schiers
  -- strict thread matches above, loose matches on Subject: below --
2012-12-24 14:39 Daniel Kiper
2013-01-24 21:38 ` Carsten Schiers
2013-01-25 10:48 Daniel Kiper
2013-01-28 16:36 ` Darren Shepherd
2013-01-28 17:40   ` David Vrabel
2013-01-29 11:53 Daniel Kiper

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