Re: [PATCH] mm/mremap: Document MREMAP_FIXED dependency on MREMAP_MAYMOVE

From: Anshuman Khandual
Date: Mon Jul 10 2017 - 22:17:02 EST


On 07/10/2017 11:01 PM, Mike Kravetz wrote:
> On 07/10/2017 06:41 AM, Michal Hocko wrote:
>> On Mon 10-07-17 17:02:11, Anshuman Khandual wrote:
>>> In the header file, just specify the dependency of MREMAP_FIXED
>>> on MREMAP_MAYMOVE and make it explicit for the user space.
>> I really fail to see a point of this patch. The depency belongs to the
>> code and it seems that we already enforce it
>> if (flags & MREMAP_FIXED && !(flags & MREMAP_MAYMOVE))
>> return ret;
>>
>> So what is the point here?
> Agree, I am not sure of your reasoning.
>
> If to assist the programmer, there is no need as this is clearly specified
> in the man page:
>
> "If MREMAP_FIXED is specified, then MREMAP_MAYMOVE must also be
> specified."

Yeah the idea was to assist the programmer and I missed the man page's
details on this. My bad.