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s=key1; t=1788232699; v=1; x=1788837499; b=iQbqfgikHpVpyMUUAMrHyUTlOaqZLRJR77DceWjUfb8vdHqANraDf/0tu3DdPGi8ibjxO5PH ZBY8IevQGiEhRdzi43/7Dl7dQ7HElvS6FHE63AoRFdOmr4mdBdaDh5Bq5pXKhI0PkBDG3xUQcC8 DDGCKvrhqABzi1za8Zqf6tQE= X-Envelope-To: linuxppc-dev@lists.ozlabs.org Received: by smtp.migadu.com with ESMTPS id 5a2cff3d3a7044ca; Tue, 01 Sep 2026 03:18:19 +0000 X-Mizu-Trace-ID: 5a2cff3d3a7044ca X-Migadu-Flow: FLOW_OUT Message-ID: <56119ff9-26f2-450c-bff9-8a4169027ba9@linux.dev> Date: Tue, 1 Sep 2026 11:18:09 +0800 X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 03/11] mm/sparse-vmemmap: open-code init_compound_tail() To: Muchun Song , Andrew Morton , David Hildenbrand , Oscar Salvador , Madhavan Srinivasan , Michael Ellerman , Jonathan Corbet Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-doc@vger.kernel.org, Muchun Song , Lorenzo Stoakes , Mike Rapoport , Nicholas Piggin , Christophe Leroy , Randy Dunlap References: <20260831075342.57563-1-songmuchun@bytedance.com> <20260831075342.57563-4-songmuchun@bytedance.com> From: Qi Zheng In-Reply-To: <20260831075342.57563-4-songmuchun@bytedance.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 8/31/26 3:53 PM, Muchun Song wrote: > init_compound_tail() is only used by vmemmap_shared_tail_page(), where > the shared tail page setup intentionally passes NULL as the compound head. > > Keeping this helper in mm/internal.h exposes that special case to the rest > of the MM code and can make the NULL head argument look generally valid. > Open-code the initialization at the only call site so the special-case use > stays local to sparse vmemmap optimization. > > No functional change intended. > > Signed-off-by: Muchun Song > --- > mm/internal.h | 9 --------- > mm/sparse-vmemmap.c | 5 ++++- > 2 files changed, 4 insertions(+), 10 deletions(-) > Acked-by: Qi Zheng Thanks, Qi