Re: [PATCH] mm: Replace all open encodings for NUMA_NO_NODE

[Anshuman Khandual <anshuman.khandual@arm.com>]

On 11/24/2018 05:14 AM, Andrew Morton wrote:
> On Fri, 23 Nov 2018 15:24:16 +0530 Anshuman Khandual <anshuman.khandual@arm.com> wrote:
> 
>> At present there are multiple places where invalid node number is encoded
>> as -1. Even though implicitly understood it is always better to have macros
>> in there. Replace these open encodings for an invalid node number with the
>> global macro NUMA_NO_NODE. This helps remove NUMA related assumptions like
>> 'invalid node' from various places redirecting them to a common definition.
>>
>> ...
>>
>> Build tested this with multiple cross compiler options like alpha, sparc,
>> arm64, x86, powerpc, powerpc64le etc with their default config which might
>> not have compiled tested all driver related changes. I will appreciate
>> folks giving this a test in their respective build environment.
>>
>> All these places for replacement were found by running the following grep
>> patterns on the entire kernel code. Please let me know if this might have
>> missed some instances. This might also have replaced some false positives.
>> I will appreciate suggestions, inputs and review.
>>
>> 1. git grep "nid == -1"
>> 2. git grep "node == -1"
>> 3. git grep "nid = -1"
>> 4. git grep "node = -1"
> 
> The build testing is good, but I worry that some of the affected files
> don't clearly have numa.h in their include paths, for the NUMA_NO_NODE
> definition.
> 
> The first thing I looked it is arch/powerpc/include/asm/pci-bridge.h. 
> Maybe it somehow manages to include numa.h via some nested include, but
> if so, is that reliable across all config combinations and as code
> evolves?
> 
> So I think that the patch should have added an explicit include of
> numa.h, especially in cases where the affected file previously had no
> references to any of the things which numa.h defines.

Fair enough. Will include numa.h in those particular files.