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t=1783329079; bh=QkFcj8l+oLXhC7aF9NZNqPGpSl0c31kzpzMlDAFV+QE=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=eG2rVnJCBidyUV6k5BBeWCCNM0F85/+WLTF1a2gL5CGxYgFLCFHCnWCFYkXxi2Gui gDSVgdzO8E6gbyBl1IAWNCCK2l/zOAT2aR1gsO7xQLSKCUDwFXdHcgwy1HRFT3xOCz eKZWz8qRLy6vOYo+YpPeOUkDqS9LlSYVzoaDIRTp+J36Z5Jg5J9M4glSVPaw1eG56j qViuc9HDHORqEf1JGyxn/2GpdcuorVLkLmARIVmJuOeYgO4vFWj0zNgi5cfqbVrP6x kvmaz3sd5ZdMQXmYDf0Her2yi6jY2CEtWmO+2AsD3bZmiL0pZUvfkuIR88Yax+Adve IU3CGjON99saw== Message-ID: Date: Mon, 6 Jul 2026 11:11:12 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 1/8] mm: fix stale ZONE_DEVICE refcount comment To: Li Zhe , akpm@linux-foundation.org, apopple@nvidia.com, arnd@arndb.de, bp@alien8.de, dave.hansen@linux.intel.com, kees@kernel.org, mingo@redhat.com, rppt@kernel.org, tglx@kernel.org Cc: linux-arch@vger.kernel.org, linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org References: <20260701090553.62691-1-lizhe.67@bytedance.com> <20260701090553.62691-2-lizhe.67@bytedance.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-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: AFE9012000A X-Stat-Signature: nzp8dd8t478edbhbdak4b9h75c4qjgo9 X-HE-Tag: 1783329079-925842 X-HE-Meta: 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 niv3h9ac T8mDuggk68R4s5MmsNrgPLzSsmyMWR0kbgnLhy7as2tkOM/0fiINk/pPT9TWPqpaAwxvbTlvWb8ULLLVjsVNDK0+uMOQusDRxL5t9NLO/27P886SMkMTEcWzXdujRXZrh2XelUnMRm6lHzrgiT6eILC1w+km+ZpMbLpcGt3bqyRj5Bjbkns2mZTOtSECfJItHHgxoHFs94kd90Hun5cy8j3bUbXjJ9SGQZN13y8bKJ+wTiN+ZFeGr/mr/J54eGj+05gkxMp1lcqkbOd1d4+IX2g7PfOBHS1WgQLr8EpgXFHUd3nfVLot5zj1bGbPonw6/AdMdhAFEKW24Dt1gVC664h/sPD/NJtt+yXsU Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 7/1/26 11:05, Li Zhe wrote: > The comment in __init_zone_device_page() still uses the old > MEMORY_TYPE_* names and implies that FS_DAX pages regain a > refcount of 1 in the free path. That no longer matches the code. > > Update the comment to describe the current policy correctly: > MEMORY_DEVICE_GENERIC pages regain a refcount of 1 in the free path, > while the remaining ZONE_DEVICE types start from 0 here and raise the > count again when the allocator or driver hands the page out. > > No functional change intended. > > Signed-off-by: Li Zhe > --- Reviewed-by: David Hildenbrand (Arm) -- Cheers, David