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t=1781163325; bh=MNI7jhwAKxOqPW4v+VQ09wX2NQrlWfNTYApqe3DsInI=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=V/Isisuv7gfQAejbPTqxpbDSnvi0ig5q/qA+XLKyTfCSr8jcF7LSpMdo6/hvEwPPS oq12h3CZSHAP0+4yCaDIIjBbB3MwWMOOBrPgjY7oIExoHErukUlsfShEFSOD6y2zWx LWZQvue9b8Fuf1sfNfbTxLdrmJZYbAP7kB9bFDLGEJWEX6OfUj2bfsb6zkw5VOzvlb xkwEMo120ESWz6G7ExnkrqeM2T3bhFVtDYsaqT7iTTzREI/RFGAzOfRPZgbK9NCnjH xHoY/ph00863vQSpQQPC3vPE9chwyQ2Z3Lg2+uJ6IHQGUn9M5qk7X8Ey5gpgqCOpHH 9bbg1zpIwnRyg== Message-ID: <07fa0325-25f9-4179-bcfa-fbef8938c40a@kernel.org> Date: Thu, 11 Jun 2026 09:35:19 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/gup: fix GUP-fast fallback for NULL-mapping order-0 folios To: Balbir Singh , Alistair Popple Cc: Zi Yan , John Hubbard , Andrew Morton , Jason Gunthorpe , Peter Xu , Mike Rapoport , LKML , linux-mm@kvack.org, Sourab Gupta References: <20260409014647.397515-1-jhubbard@nvidia.com> <4d6c1af0-dee5-4f1b-b74c-2ebc23de7baf@kernel.org> <08afbec2-bbe7-4e8a-8d99-8a5eaecaeee7@nvidia.com> <5aae8c80-e886-47b1-a1e1-4e91771f3492@kernel.org> <7A8AEDE1-C28F-4490-8A2E-72E4E8D0E78F@nvidia.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: AA2FBC0004 X-Rspam-User: X-Stat-Signature: 7gmeunfr58hohh8jawcemospy41od157 X-HE-Tag: 1781163326-810130 X-HE-Meta: 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 QiuNPZuP m9Ay7JijCoDZ7ejrIf2E9zcDdXOGAYF9MvbBIn4Ve5ORjm6bdiYlrNadeLGTLe3d8BxMAv28KQMHqyKHHKWlaDdT4ef49JlGz1iWWVaD9zt8tMZDSarYzNcVTc9DKTmT/5SnO8bGadInEk09qOECvOYlhi5zm8UKDSiXLWn/i3AS3mNo1K4dL7r7nHL2AFhecI6hvXwR7HOdVznkS44m8iqIjoac1eyHofIIAaIT3irYPph45wYckir+Wh6p0mv3tBtU+lxzHkS+PacefPMuex0SVSWCQ3cZ/a3N5OlgTvMTEl7BDUkG6hiGpHg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 6/11/26 03:12, Balbir Singh wrote: > On Thu, Jun 11, 2026 at 10:49:59AM +1000, Alistair Popple wrote: >> On 2026-06-06 at 02:20 +1000, Zi Yan wrote... >>> >>> >>> Right, I will work on my solution soon. Meanwhile, this change >>> is simpler and can be easily back ported. >> >> Thanks. >> >>> BTW, should it be back ported to older kernels? >> >> Yes to any with f002882ca369 ("mm: merge folio_is_secretmem() and >> folio_fast_pin_allowed() into gup_fast_folio_allowed()") - we have got bug >> reports as a result of the lowered perf that commit causes. >> >> - Alistair >> > > Ping @akpm to pick this up, if there is no objection @david Fine with me Acked-by: David Hildenbrand (Arm) -- Cheers, David