[Linaro-mm-sig] [PATCHv17 0/11] Contiguous Memory Allocator

[sandeep patil]

2011/11/18 Michal Nazarewicz <mina86 at mina86.com>:
> On Fri, 18 Nov 2011 22:20:48 +0100, sandeep patil <psandeep.s at gmail.com>
> wrote:
>>
>> I am running a simple test to allocate contiguous regions and write a log
>> on
>> in a file on sdcard simultaneously. I can reproduce this migration failure
>> 100%
>> times with it.
>> when I tracked the pages that failed to migrate, I found them on the
>> buffer head lru
>> list with a reference held on the buffer_head in the page, which
>> causes drop_buffers()
>> to fail.
>>
>> So, i guess my question is, until all the migration failures are
>> tracked down and fixed,
>> is there a plan to retry the contiguous allocation from a new range in
>> the CMA region?
>
> No.  Current CMA implementation will stick to the same range of pages also
> on consequent allocations of the same size.
>

Doesn't that mean the drivers that fail to allocate from contiguous DMA region
will fail, if the migration fails?

~ sandeep