Re: [PATCH 08/10] xen/arm: introduce reserved_page_list

[Jan Beulich <jbeulich@xxxxxxxx>]

On 18.05.2021 10:38, Penny Zheng wrote:
> Hi Jan
> 
>> -----Original Message-----
>> From: Jan Beulich <jbeulich@xxxxxxxx>
>> Sent: Tuesday, May 18, 2021 3:39 PM
>> To: Penny Zheng <Penny.Zheng@xxxxxxx>
>> Cc: Bertrand Marquis <Bertrand.Marquis@xxxxxxx>; Wei Chen
>> <Wei.Chen@xxxxxxx>; nd <nd@xxxxxxx>; xen-devel@xxxxxxxxxxxxxxxxxxxx;
>> sstabellini@xxxxxxxxxx; julien@xxxxxxx
>> Subject: Re: [PATCH 08/10] xen/arm: introduce reserved_page_list
>>
>> On 18.05.2021 07:21, Penny Zheng wrote:
>>> Since page_list under struct domain refers to linked pages as gueast
>>> RAM allocated from heap, it should not include reserved pages of static
>> memory.
>>>
>>> The number of PGC_reserved pages assigned to a domain is tracked in a
>>> new 'reserved_pages' counter. Also introduce a new reserved_page_list
>>> to link pages of static memory. Let page_to_list return
>>> reserved_page_list, when flag is PGC_reserved.
>>>
>>> Later, when domain get destroyed or restarted, those new values will
>>> help relinquish memory to proper place, not been given back to heap.
>>>
>>> Signed-off-by: Penny Zheng <penny.zheng@xxxxxxx>
>>> ---
>>>  xen/common/domain.c     | 1 +
>>>  xen/common/page_alloc.c | 7 +++++--
>>>  xen/include/xen/sched.h | 5 +++++
>>>  3 files changed, 11 insertions(+), 2 deletions(-)
>>
>> This contradicts the title's prefix: There's no Arm-specific change here at 
>> all.
>> But imo the title is correct, and the changes should be Arm-specific. There's
>> no point having struct domain fields on e.g. x86 which aren't used there at 
>> all.
>>
> 
> Yep, you're right.
> I'll add ifdefs in the following changes.

As necessary, please. Moving stuff to Arm-specific files would be
preferable.

Jan