From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C4BCFCA5FBE for ; Wed, 30 Sep 2026 10:03:13 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4hvrG75DJVz2yqT; Wed, 30 Sep 2026 20:03:11 +1000 (AEST) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip="2001:41d0:1004:224b::9d" ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1790762591; cv=none; b=QgT7ZZ2EnvuT7Wmqg8rvZ25sSdZC+KPcMhtSMOIizpTXYRlaPH2hwakCHU10IDksP9C9fM8HmovIYc5KE7wBun4oNY+GGAwNJyOP1xw4Fy7C+vWlgVqJoVhy83mh+eWqu/UnyjL0iKFbT2hOJckZPBJJ04wuLwL5tj2j46QnsHl0ky3xzVR9EVeu92twC5YnYL603IiBUrplH7NNsVHl647pCzF6Bucmpc3VAV4h8ofjQT/AKkBTgTcnrF2BmcOUEcxOsR5tKNQ+OmSHr2lPze3NnSCp6Uk2KPwdu4LffFJC+sKTCs1eBs9/Ggup6q/IhxohG6jdqkvPi4FngnVGWg== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1790762591; c=relaxed/relaxed; bh=6qRsSUfuBnTMx2Y9L6KCbkAYKGnB+pDv2tFE4p6k81k=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=D5rKs+WaaDKICvCAeG69TmCxBMkQAJaxbg3jOJBiV/BqH0UerfMOd2AbDyO1Ss/mavBWYC50lURgP9zg2ijbBkSCYlQWPx9K0PsJ8ukkCT+8UOECFjPdD8TehXEpZJx/RmO+0efkjjTv6uXxHcbk9NUB+sZc0UOi743LL0LQUh/XRuY9MQeMjOrIFb7GfopbJ0g7PbnU8LB4to1P3yt6xhBX4PYm0/akhxhIIH+YIA9o59zmjICK01Eyb3PgOcsnzy3jScYk6gRuxSbewh1YY+PnafcPp3AAiL7GgYXbToriGtz2Ym2ebqsHXfEC8KOSKv/61FXW8H1ozqWZvq0foA== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=linux.dev; dkim=pass (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=MfkHMdka; dkim-atps=neutral; spf=pass (client-ip=2001:41d0:1004:224b::9d; helo=mta0.migadu.com; envelope-from=lance.yang@linux.dev; receiver=lists.ozlabs.org) smtp.mailfrom=linux.dev Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=MfkHMdka; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.dev (client-ip=2001:41d0:1004:224b::9d; helo=mta0.migadu.com; envelope-from=lance.yang@linux.dev; receiver=lists.ozlabs.org) Received: from mta0.migadu.com (out-157.mta0.migadu.com [IPv6:2001:41d0:1004:224b::9d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4hvrG44rWRz2yjN for ; Wed, 30 Sep 2026 20:03:06 +1000 (AEST) X-Envelope-To: linuxppc-dev@lists.ozlabs.org DKIM-Signature: a=rsa-sha256; bh=6qRsSUfuBnTMx2Y9L6KCbkAYKGnB+pDv2tFE4p6k81k=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1790762567; v=1; x=1791367367; b=MfkHMdkaZFeZ63PXyuvaJ9E6glbryTwVflyII1EBXG9UvkZF5eI7Oq52rSTfVLjfFsC1DQGh 2Z1dsZlDdoMPiQZ9UtihJSHd7yfDlfskF94GF2nKN7Ei2AWEmZaRkPTSU+XDaaTgGUvluLXgcky ZbwRYYmSbBhwEZmdmKbQRIbw= X-Envelope-To: linuxppc-dev@lists.ozlabs.org Received: by smtp.migadu.com with ESMTPS id 702ad52dc12a4244; Wed, 30 Sep 2026 10:02:36 +0000 X-Mizu-Trace-ID: 702ad52dc12a4244 X-Migadu-Flow: FLOW_OUT From: Lance Yang To: songmuchun@bytedance.com Cc: maddy@linux.ibm.com, rppt@kernel.org, akpm@linux-foundation.org, david@kernel.org, mpe@ellerman.id.au, npiggin@gmail.com, chleroy@kernel.org, ritesh.list@gmail.com, sshegde@linux.ibm.com, ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, surenb@google.com, mhocko@suse.com, qi.zheng@linux.dev, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, muchun.song@linux.dev, Lance Yang Subject: Re: [PATCH v3 2/6] mm/sparse-vmemmap: support device DAX in common vmemmap path Date: Wed, 30 Sep 2026 18:02:26 +0800 Message-ID: <20260930100226.23688-1-lance.yang@linux.dev> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20260929053231.66085-3-songmuchun@bytedance.com> References: <20260929053231.66085-3-songmuchun@bytedance.com> 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 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On Tue, Sep 29, 2026 at 01:32:27PM +0800, Muchun Song wrote: >The common vmemmap population path cannot yet handle optimized Device DAX >mappings on its own. It uses pfn_to_zone() to find the shared tail page, >but Device DAX populates its vmemmap at runtime before the ZONE_DEVICE span >is initialized. > >Teach the common path to use device_zone() for runtime optimized vmemmap >population while retaining pfn_to_zone() for early boot. This allows the >same path to support both early boot mappings and Device DAX. > >The backing PFN supplied by the Device DAX-specific population path is no >longer used, allowing the redundant lookup and population code to be >removed later. > >Signed-off-by: Muchun Song >Acked-by: Qi Zheng >--- Nothing jumped out at me, feel free to add: Reviewed-by: Lance Yang