Re: [PATCH v2 3/3] mm: cma: release trigger

[Sasha Levin <sasha.levin@oracle.com>]

On 01/27/2015 03:10 AM, Joonsoo Kim wrote:
>> +		if (mem->n <= count) {
>> > +			cma_release(cma, mem->p, mem->n);
>> > +			count -= mem->n;
>> > +			kfree(mem);
>> > +		} else {
>> > +			cma_release(cma, mem->p, count);
>> > +			mem->p += count;
>> > +			mem->n -= count;
>> > +			count = 0;
>> > +			cma_add_to_cma_mem_list(mem);
>> > +		}
>> > +	}
> If order_per_bit is not 0 and count used in cma_release() is
> different with the count used in cma_alloc(), problem could
> occur since bitmap management code can't handle that situation.
> 
> Could we just disable this case in this testing module?

How should it behave then? Just free a max of 'count' pages and
stop beforehand if we're going to go over it?


Thanks,
Sasha