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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3FDF7C79FB9 for ; Thu, 10 Sep 2026 08:34:03 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4639A6B0096; Thu, 10 Sep 2026 04:34:02 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 412816B0098; Thu, 10 Sep 2026 04:34:02 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 351F66B0099; Thu, 10 Sep 2026 04:34:02 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 121126B0096 for ; Thu, 10 Sep 2026 04:34:02 -0400 (EDT) Received: from smtpin09.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 9EE67802B2 for ; Thu, 10 Sep 2026 08:34:01 +0000 (UTC) X-FDA: 85197189882.09.1151A15 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf14.hostedemail.com (Postfix) with ESMTP id 1608A100009 for ; Thu, 10 Sep 2026 08:33:59 +0000 (UTC) Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=CazkhZSv; spf=pass (imf14.hostedemail.com: domain of osalvador@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=osalvador@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1789029240; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=htWrCuWloy0NONsft45RDstF/ATea72DavKG8+QtMK4=; b=J/1nqniRkyFCOEsT3ECaY+SOcuW4uc0VlcZP1AH5b84uGWeovyqkQWfergvvBM76A+vPjm m+y7GOJLjG+xgL7pg0qwKoxMHxANfyiZLrRpYNYHD6ej7Uzur8sE4PsW3J+OQeskdLDkC8 QHx8iSbVKw4IWgGNrrtXVGxniR/zHqk= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1789029240; b=UhJN7/i9oPoXUppXYr0UqLT4c+PqJtp7NK+F7begOiGYbtgZ7R6XNcNWiuguTpvfUTz3Zc MRR5vwajaP0K80wyUt+wtA+9yF/wSM9ceyyr/pqckG6MHH6Pni0+0pzMjPniIsxCoeJQpL ZVmxzm/nVVGIWcAaKE99JcxiAopRdNM= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=CazkhZSv; spf=pass (imf14.hostedemail.com: domain of osalvador@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=osalvador@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 70B49601F0; Thu, 10 Sep 2026 08:33:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DA8C81F000FF; Thu, 10 Sep 2026 08:33:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789029239; bh=htWrCuWloy0NONsft45RDstF/ATea72DavKG8+QtMK4=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=CazkhZSvT+O0NgogGiXHI0lYcotwsei+QChUnDurF+HYFaqB31jqAAsP+ioj1RnJa slgoF+ChAAr/n4Lv1nBu2JaW3o+ffaESC4PwPQHVefTX1rJX0ZIIobfByVZPcIh8yU cx/VjCtD++UBLeRhzdko4P4UG+Pz1IlPG0jvfelVuUSkAqdjNHPkX4ImE2iLnVR4zh ECN3fzt4IyI8LStfLku08boRFArVqEJj1jo7jmqw3U74L2Mq2EXSNraAwkdMbliJHb jqTXTw4P0h0kyaFkuFMztWx28m4l1WJ72RCkKhiHM7UOl5XVdmfYEX46V1wJWF6/8J lsV+jOV4QvQfw== Date: Thu, 10 Sep 2026 10:33:50 +0200 From: "Oscar Salvador (SUSE)" To: "David Hildenbrand (Arm)" Cc: Andrew Morton , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kairui Song , Qi Zheng , Shakeel Butt , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , Baolin Wang , Brendan Jackman , Johannes Weiner , Zi Yan , Oscar Salvador , Greg Kroah-Hartman , "Rafael J. Wysocki" , Danilo Krummrich , Jan Kiszka , Kieran Bingham , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-cxl@vger.kernel.org, driver-core@lists.linux.dev, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 08/12] mm/sparse: move __highest_used_section_nr handling Message-ID: References: <20260909-b4-sparsemem_cleanups-v1-0-008fc8d579fe@kernel.org> <20260909-b4-sparsemem_cleanups-v1-8-008fc8d579fe@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260909-b4-sparsemem_cleanups-v1-8-008fc8d579fe@kernel.org> X-Rspamd-Server: rspam04 X-Rspam-User: X-Stat-Signature: zmtrmbqf5jjq38u9gr5dpk9sbybxhb7b X-Rspamd-Queue-Id: 1608A100009 X-HE-Tag: 1789029239-814878 X-HE-Meta: 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 tVAkEpEz VsyKLQHai2Nl4Z/xuR4SG4r2xUNhA47LvndY1ImdLKdtEq+WtCez1rwo6zT77NsuonXdTYoPZU+Gys9Q14xnWirsCROUGT+s2R5AWwpVNPt/WuaXZVLCUe5CiyQHEgnDLXPvmeQcIprTgOkNtXp1Z5S6hlC6dFMx50Ur5nUpW2PI02qJzObYJVw4v/NFOnfOWUIr+2iD5u+kV7LLP4YXIORx7Z0tI0oQlrhfrH4RiVzunR+IdEPTjcKqPpDI8lEe3JULu+nQARPxmIds= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Sep 09, 2026 at 03:33:01PM +0200, David Hildenbrand (Arm) wrote: > Let's move it to sparse_init_one_section(). However, to keep early > boot processing working, we also have to initialize it in > sparse_sections_init(). > > Should we use READ_ONCE/WRITE_ONCE with __highest_used_section_nr? > Probably, something for another day. What is the worry there? sparse_init_one_section() calls should run sequentally due to the memhotplug lock, so there should not be parallel updates there? -- Oscar Salvador SUSE Labs