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Date: Sun, 13 Jan 2019 18:35:55 +0100
From: Michal Hocko <mhocko@kernel.org>
To: Anshuman Khandual <anshuman.khandual@arm.com>
Subject: Re: [PATCH] mm: Introduce GFP_PGTABLE
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On Sat 12-01-19 15:56:38, Anshuman Khandual wrote:
> All architectures have been defining their own PGALLOC_GFP as (GFP_KERNEL |
> __GFP_ZERO) and using it for allocating page table pages. This causes some
> code duplication which can be easily avoided. GFP_KERNEL allocated and
> cleared out pages (__GFP_ZERO) are required for page tables on any given
> architecture. This creates a new generic GFP flag flag which can be used
> for any page table page allocation. Does not cause any functional change.

I agree that some unification is due but GFP_PGTABLE is not something to
expose in generic gfp.h IMHO. It just risks an abuse. I would be looking
at providing asm-generic implementation and reuse it to remove the code
duplication. But I haven't tried that to know that it will work out due
to small/subtle differences between arches.

> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
-- 
Michal Hocko
SUSE Labs