From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta1.migadu.com (out-125.mta1.migadu.com [95.215.58.125]) (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 DABE2375AA8 for ; Mon, 28 Sep 2026 13:50:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.125 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790603426; cv=none; b=WaFgTMvar6Potavr54WqOdzCPqq3V6DDkUvZkTKp4Liu69wrJWB9lkVRmN1TlQNdM3MZFpnmn0F7ynMk9eG8SqUHTvDjCnnFB+jgGMos/EP1zK6iEb6fQBiGitYEHsg/MQUJ1nTVvSrFbx8RGDeT6GHg1F0uxGcgVrf27LPRUmU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790603426; c=relaxed/simple; bh=kwGEFPYPtNOaPfcKsHGyvboh3/0JIjAHnUCjf3u1ZsI=; h=Content-Type:Mime-Version:Subject:From:In-Reply-To:Date:Cc: Message-Id:References:To; b=ELz2sXkkL8cG9xlrznu4wW9WfVaaD6uRD1b2RBxJjFg9Zp00+VFoJFxcUfFWfrSENYIe2f3943ZoT3bq6rcJ+fSKfaKk7OXOLZw74cHTaGZ/yN6bEuacE+bxCVF/K5YVDjnd9AbYk1rdga316DHNlz24s41APrEXxpjflicUnq0= 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=Vyye3Oeb; arc=none smtp.client-ip=95.215.58.125 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="Vyye3Oeb" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=kwGEFPYPtNOaPfcKsHGyvboh3/0JIjAHnUCjf3u1ZsI=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1790603419; v=1; x=1791208219; b=Vyye3OebcY+xj2trKEReAE1SMObxnH934kgvJ3fOy1Rw/EgoQWB6GCFxv3cajfRyBcrxDxzY 2LAW6o1O1ef+sLeZE7Aa8/5RZfOI8Wh/y4k0kQ+McLtqbe8MwWemFlFTnUcpXhE93OIyrOSJz3G yuU3XuIgD9pfGdDKrSmmFaoU= X-Envelope-To: linux-kernel@vger.kernel.org Received: by mta11.migadu.com with ESMTPS id e0d00ebac706a868; Mon, 28 Sep 2026 13:50:14 +0000 X-Mizu-Trace-ID: e0d00ebac706a868 X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset=us-ascii Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3901.100.1.1.11\)) Subject: Re: [PATCH v2 0/6] mm: Unify device DAX and HugeTLB vmemmap population paths From: Muchun Song In-Reply-To: <607759bf-59f2-4ad6-b95b-e780ed2acba3@kernel.org> Date: Mon, 28 Sep 2026 21:49:55 +0800 Cc: Muchun Song , Madhavan Srinivasan , Mike Rapoport , Andrew Morton , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Lorenzo Stoakes , "Liam R . Howlett" , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko , Qi Zheng , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Content-Transfer-Encoding: quoted-printable Message-Id: <8385F749-0F72-494E-9CA2-2E433A066712@linux.dev> References: <20260924075259.2013039-1-songmuchun@bytedance.com> <607759bf-59f2-4ad6-b95b-e780ed2acba3@kernel.org> To: "David Hildenbrand (Arm)" X-Mailer: Apple Mail (2.3901.100.1.1.11) > On Sep 28, 2026, at 20:44, David Hildenbrand (Arm) = wrote: >=20 > On 9/24/26 09:52, Muchun Song wrote: >> This series is split out from the earlier, larger series "mm: = Generalize >> HVO for HugeTLB and device DAX" [1]. While the parent series = generalizes >> vmemmap optimization across HugeTLB and device DAX, this subset = addresses >> a single, self-contained step: unifying their vmemmap population = paths. >>=20 >> After the preceding Device DAX conversion, both HugeTLB and Device = DAX >> describe optimized vmemmap mappings through memory-section metadata = and >> use per-zone shared tail vmemmap pages. The generic code, however, = still >> carries a Device DAX-specific population flag and compound-page = population >> path, along with arguments and helpers needed only by that path. >>=20 >> This series first removes VMEMMAP_POPULATE_DAX and moves selection = and >> reference handling for the shared tail page into the common vmemmap >> population path. It then removes the generic Device DAX-specific >> compound-page population path and routes section vmemmap population >> through vmemmap_populate(). The powerpc radix path continues to use = its >> architecture-specific compound-page population implementation for >> optimizable sections. >>=20 >> The remaining patches remove the unused ptpfn argument, open-code >> vmemmap_populate_address() now that no caller needs its returned PTE, = and >> add a warning for inconsistent zone initialization of shared tail = vmemmap >> pages. >>=20 >> This is the fourth smaller step toward the broader HVO = generalization. >> After this series, HugeTLB and Device DAX use the same population = model >> instead of parallel generic paths, while powerpc keeps its >> architecture-specific implementation. >>=20 >> [1] = https://lore.kernel.org/all/20260513130542.35604-1-songmuchun@bytedance.co= m/ >=20 > How does this series relate to >=20 > = https://lore.kernel.org/r/20260927025441.741633-1-songmuchun@bytedance.com= This series is based on the v4 version [1] of the series you pointed = out. When I was sending the current series, the v4 version of that series had = already been in mm-new for some time, so I sent the v2 version of the current = series. However, a couple of days ago the kernel test bot reported an issue, and = this issue cannot be easily fixed with a simple fixup. So I updated that = series to a v5 version. Therefore, the current series needs to be rebased on top of the v5 = version of the series you pointed out, and then sent as a new v3 version before it = can be properly applied or reviewed. If you're planning to review this series, I'd suggest waiting for my = rebased version. [1] = https://lore.kernel.org/all/20260916064341.1825793-1-songmuchun@bytedance.= com/ Thanks, Muchun >=20 > ? >=20 > --=20 > Cheers, >=20 > David