Re: Possible regression: XEN 4.0.0 total_memory decrease

[Keir Fraser <keir.fraser@eu.citrix.com>]

I've fixed this regression as xen-unstable:21190 and xen-4.0-testing:21114.
The fix will appear in Xen 4.0.1.

 Thanks,
 Keir

On 15/04/2010 19:05, "Keir Fraser" <keir.fraser@eu.citrix.com> wrote:

> Ah, hm, I think this is a bug in total memory reporting only. I think the
> memory is still there in the free pools though. :-) How does xm info's
> free_memory compare in the two cases? I bet it's a lot closer than 150MB
> (assuming dom0 is allocated the same amount of memory in both cases, e.g.,
> by explicitly specifying dom0_mem=xxx on Xen command line).
> 
>  -- Keir
> 
> On 15/04/2010 18:33, "Alex Williams" <awilliams@iweb.com> wrote:
> 
>> Hello,
>> 
>> Both builds run a 64-bit Xen kernel and 64-bit Dom0 kernel.
>> 
>> (XEN)  Xen  kernel: 64-bit, lsb, compat32
>> (XEN)  Dom0 kernel: 64-bit, lsb, paddr 0xffffffff80200000 ->
>> 0xffffffff805d388c
>> 
>> As for the RAM:
>> 
>> Xen 3.4.2: (XEN) System RAM: 3946MB (4041012kB)
>> Xen 4.0.0: (XEN) System RAM: 4084MB (4182064kB)
>> 
>> I have also verified with only 2048MB installed in the system. Here are
>> the results:
>> 
>> Xen 3.4.2: (XEN) System RAM: 2036MB (2084912kB)
>> Xen 4.0.0: (XEN) System RAM: 1898MB (1943860kB)
>> 
>> Still 150MB RAM missing... it appears this problem is static and
>> independant of the amount of RAM installed in the system.
>> 
>> Regards,
>> 
>> 
>> 
>> Keir Fraser wrote:
>>> Are the hypervisor and dom0 kernel 64-bit or 32-bit? Xen prints a message
>>> "System RAM: xxx" early during boot. Do these differ significantly for you
>>> between 3.4.2 and 4.0.0?
>>> 
>>>  K.
>>> 
>>> On 15/04/2010 16:54, "Alex Williams" <awilliams@iweb.com> wrote:
>>> 
>>>> Hello,
>>>> 
>>>> I noticed a significant *decrease* (150MB) in "total_memory" on a host
>>>> build using XEN 4.0.0 with kernel 2.6.18.
>>>> 
>>>> Here are the details:
>>>> 
>>>> Server = 4096MB RAM
>>>> XEN 3.4.2 + kernel 2.6.18: xm info | grep total_memory = 4084
>>>> XEN 4.0.0 + kernel 2.6.18: xm info | grep total_memory = 3946
>>>> 
>>>> The exact same kernel config file was used for both builds. I also made
>>>> sure there is absolutely no difference on the hosts (while the builds
>>>> are created on a different machine).
>>>> 
>>>> This seems like a regression, unless someone can provide suggestions on
>>>> how to correct this?
>>>> 
>>>> Thanks.
>>>> 
>>> 
>>> 
>>> 
>>> _______________________________________________
>>> Xen-devel mailing list
>>> Xen-devel@lists.xensource.com
>>> http://lists.xensource.com/xen-devel
>>> 
> 
> 
> 
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