From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta1.migadu.com (out-106.mta1.migadu.com [95.215.58.106]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0B95944062F for ; Tue, 1 Sep 2026 03:18:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.106 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788232704; cv=none; b=hWS0aWQA/MFSjDDisf5waxU2p6D9nLIxUg23iC2hXsxQDWV2A14dgIm9drxcwEldNfLA+e3gBv7zid/fFhNuiYq2YXrRYgOAHeJl8HJdCI9JzrKGqh6DoevosCqHaxPSl+3A2TKZFWqVR3pnRemYFTm+hp0b0X/DlE/Gji7N9VQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788232704; c=relaxed/simple; bh=+yvmAaiXJSQhUiY43hR2AcbPXHGoUIEk5aWBZqakNg0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=CoKITwSKyOwX1RlK1/y2h9pOwvQ4wEM1g7nwiiy7AIvwWwxzTmV0uqEiSir8sG8+XhZjYF9ZpODYo98TQzjbrFCUlPKUbuhZGmJ3/dUSUINI4JtdBd/tAJBTpkK3MjREhHo9De9vgVwlghLNjOtroNQiHb/niTt/3Ku2bD+DDvQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=iQbqfgik; arc=none smtp.client-ip=95.215.58.106 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="iQbqfgik" X-Envelope-To: linux-doc@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=+yvmAaiXJSQhUiY43hR2AcbPXHGoUIEk5aWBZqakNg0=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1788232699; v=1; x=1788837499; b=iQbqfgikHpVpyMUUAMrHyUTlOaqZLRJR77DceWjUfb8vdHqANraDf/0tu3DdPGi8ibjxO5PH ZBY8IevQGiEhRdzi43/7Dl7dQ7HElvS6FHE63AoRFdOmr4mdBdaDh5Bq5pXKhI0PkBDG3xUQcC8 DDGCKvrhqABzi1za8Zqf6tQE= X-Envelope-To: linux-doc@vger.kernel.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 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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