Re: [PATCH v6 2/6] mm/cma: introduce new zone, ZONE_CMA

[Chen Feng]

On 2016/11/7 14:15, Joonsoo Kim wrote:
> On Tue, Nov 01, 2016 at 03:58:32PM +0800, Chen Feng wrote:
>> Hello, I hava a question on cma zone.
>>
>> When we have cma zone, cma zone will be the highest zone of system.
>>
>> In android system, the most memory allocator is ION. Media system will
>> alloc unmovable memory from it.
>>
>> On low memory scene, will the CMA zone always do balance?
> 
> Allocation request for low zone (normal zone) would not cause CMA zone
> to be balanced since it isn't helpful.
> 
Yes. But the cma zone will run out soon. And it always need to do balance.

How about use migrate cma before movable and let cma type to fallback movable.

https://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg1263745.html

>> Should we transmit the highest available zone to kswapdï
> 
> It is already done when necessary.
> 
> Thanks.
> 
> 
> .
>