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Message-ID: <3fbfb5fc-83a4-49da-ba75-9b671ffe0569@arm.com>
Date: Tue, 30 Jan 2024 09:56:10 +0530
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Subject: Re: [PATCH RFC v3 01/35] mm: page_alloc: Add gfp_flags parameter to
 arch_alloc_page()
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To: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: catalin.marinas@arm.com, will@kernel.org, oliver.upton@linux.dev,
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References: <20240125164256.4147-1-alexandru.elisei@arm.com>
 <20240125164256.4147-2-alexandru.elisei@arm.com>
 <de0c74b3-0c7d-4f21-8454-659e8b616ea7@arm.com> <ZbePA2dGE6Vs-58t@raptor>
From: Anshuman Khandual <anshuman.khandual@arm.com>
In-Reply-To: <ZbePA2dGE6Vs-58t@raptor>
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On 1/29/24 17:11, Alexandru Elisei wrote:
> Hi,
> 
> On Mon, Jan 29, 2024 at 11:18:59AM +0530, Anshuman Khandual wrote:
>> On 1/25/24 22:12, Alexandru Elisei wrote:
>>> Extend the usefulness of arch_alloc_page() by adding the gfp_flags
>>> parameter.
>> Although the change here is harmless in itself, it will definitely benefit
>> from some additional context explaining the rationale, taking into account
>> why-how arch_alloc_page() got added particularly for s390 platform and how
>> it's going to be used in the present proposal.
> arm64 will use it to reserve tag storage if the caller requested a tagged
> page. Right now that means that __GFP_ZEROTAGS is set in the gfp mask, but
> I'll rename it to __GFP_TAGGED in patch #18 ("arm64: mte: Rename
> __GFP_ZEROTAGS to __GFP_TAGGED") [1].
> 
> [1] https://lore.kernel.org/lkml/20240125164256.4147-19-alexandru.elisei@arm.com/

Makes sense, but please do update the commit message explaining how
new gfp mask argument will be used to detect tagged page allocation
requests, further requiring tag storage allocation.