Re: Restart domU failure (memory allocation issue)

[Julien Grall <julien.grall@linaro.org>]

(Adding ARM people in CC)

On 13/03/14 18:33, Oleksandr Tyshchenko wrote:
> Hello, all.

Hello Oleksandr,

> I am working with DRA7 (OMAP5) platform and I am using XEN 4.4 and
> Kernel 3.8 for both domains.
> As we still have 1:1 mapping for domU we need to allocate memory (1024
> MB in our case) for it at one chunk.
>
> The issue is that I can't create domain again after destroying it (I
> am destroying domain by a "xl destroy" command) because we no longer
> have contiguous memory region and as result allocation failed.
>
> It seems, we have memory leak. I see that not all memory is freed
> after domain destroy.
> I see that some pages (which were allocated for kernel segment) don't
> returned to the heap.

I gave a try on Xen 4.4 with normal guest (e.g without the 1:1 mapping) 
and I don't find any memory leaks. How do you create the 1:1 mapping for 
the guest?

> / # xl list
> Name                                        ID   Mem VCPUs      State   Time(s)
> Domain-0                                     0   128     2     r-----       4.1
> (null)                                       1     5     2     --p--d       0.9

It seems that your domain is not completely destroyed. It may be because 
some pages still belongs to the domain.

Xen will free a page only when the reference count is 0, do you have 
keep some mapping in dom0? (for instance in libxl).

Regards,

-- 
Julien Grall