From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EC90B1A6806 for ; Fri, 28 Aug 2026 04:20:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787890860; cv=none; b=eanHgsxRUnyTHmPMOmyNCsPQFX/DTejIs7VegPmLeuQuReBV1Qp5fjAsVZiZ3xQnJ+RLNk00RWzGCbQgXyqHXLq67qYI7w4GYrN0ANp1t2TexRoqVQcQZbVnxvaw9uS+jpPRBQcOJdq3jGHK1DlQL8fOfisNmBPTdsctNI/2tzQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787890860; c=relaxed/simple; bh=Fpj/D1+n+MtEOOr2BiKuEo2/UxpLlUdcI8LnwOsahQU=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=TwLVazmxAGsy6gndqgWKOk5MbND6dZiMRnKP12d0jSbYy5MuOHCd0+J1COH2t1HkhmCNvW0rPXHcNRjoeAaHW6ZngZWNzVQD+FbjtBWgH0hsd3qYtV7AneHC0tSRrluRf5XUzetVsya8qkOl8voowyuskpkd9EzaT8xlOiay9Oc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=zjLx3msp; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="zjLx3msp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E14971F000E9; Fri, 28 Aug 2026 04:20:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1787890858; bh=Ms9ElGpndu/p4gAL+/SKqDdyKJI1gRddTa0Oo3jugRg=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=zjLx3mspMsqvC1HC1b68Q2TAPPBiegAYK1vMXjHWbHsBl6g/VajdsK5FR+eAyvi1F h9ITZW4jAjHz3Jf/1OaOPRdXpT2i0FRvzG+vdptj0x7fqAtE3Fd9WftVeStw48HUK7 y785cuFytGJWnBqFNF+dHyeUqtyv5WtSX/XEmMzQ= Date: Thu, 27 Aug 2026 21:20:57 -0700 From: Andrew Morton To: Muchun Song Cc: Oscar Salvador , David Hildenbrand , Mike Rapoport , Vlastimil Babka , Lorenzo Stoakes , Michal Hocko , David Laight , "Liam R . Howlett" , Suren Baghdasaryan , Qi Zheng , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Muchun Song Subject: Re: [PATCH v5 00/17] mm: Introduce section-based vmemmap optimization for HugeTLB Message-Id: <20260827212057.37cf374d95450d325e5fce63@linux-foundation.org> In-Reply-To: <20260825084608.47437-1-songmuchun@bytedance.com> References: <20260825084608.47437-1-songmuchun@bytedance.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Tue, 25 Aug 2026 16:45:51 +0800 Muchun Song wrote: > HugeTLB vmemmap optimization currently has its own early boot setup > path. It pre-populates optimized vmemmap mappings before the normal > sparse-vmemmap population code runs, and sparsemem carries > SPARSEMEM_VMEMMAP_PREINIT only to support that special case. > > That makes the HugeTLB vmemmap optimization path harder to share with > other users of sparse-vmemmap optimization and leaves a fair amount of > HugeTLB-specific boot-time state in the generic memory initialization > flow. > > This series introduces section-based vmemmap optimization support in > the sparse-vmemmap code and switches HugeTLB bootmem pages over to it. > Instead of having HugeTLB pre-populate optimized vmemmap mappings > itself, HugeTLB now records the compound page order in the corresponding > memory sections. The generic sparse-vmemmap population path can then > allocate or reuse shared tail vmemmap pages based on section metadata. Thanks, I've added this to mm.git's mm-new branch. After -rc1 I'll move it into the mm-unstable branch, and thereby into linux-next.