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 47DC43A2E0A; Thu, 9 Jul 2026 23:57:34 +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=1783641455; cv=none; b=AL7ANBPjN3J/L3sdUTTqlGgh+w9YwgYtzfhGjGypFb1Ah9hiaJm08sSPbnyin1VZYDpiXHr8sepHIZBVYfDCRGm/5XOF7uL8lHGKvN/1KKnWRtUvY7dcY365GJhIsdlR/dl51/Bd5Dp47Bp4Q5/t2dteFPsuaLwN0JQKO9d8ED0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783641455; c=relaxed/simple; bh=ijeMi1ynINCbfpsysZOXJoU1MZ/yQ6o1QBJh/Ou0gAQ=; h=Date:From:To:Cc:Message-ID:In-Reply-To:References:Subject: Mime-Version:Content-Type; b=sNhPR/87LSf050OAfQ53FuqQRj7IV/6wsOjLbWlyaot6XMUDNFfAWJw3Y8cC2SKuTozo3XCsPGNB72S4kdL+MFMwkuJtL6/s7EfxdAK3GZhuzXC/zpGRwJqUbC/GbNEsQm+rB76CPBglAMqD6+pCpfytxlcPbk4VOZzT31bYXTU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VGvMFIuG; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VGvMFIuG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3DD251F000E9; Thu, 9 Jul 2026 23:57:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783641454; bh=NL6KkE+XGM13rjECEPlDsP8sDmlO2+4iY80eSoJW34k=; h=Date:From:To:Cc:In-Reply-To:References:Subject; b=VGvMFIuGD04PIRzU/JMeGvWpJXoTWA+IBrWJ4DETddqsvMfFiGavTTa9l63r0ClWv X2UUQqNqpZqczRFyLqhZ+Zy8m15reHdQPTxmbUIl38NqaY/9+pMPbWiYC4uxdsvauQ wiyhThJeiv2vh4H7xyufBRg8Jf3VvutnySvhp/UkfByFzJVEb/o6mL59688vpOGA8E /KtI4FyfFU6/yE1N8/6ajHygAZKQzXhv4MUIjJQ7ZlAJqRmRYhZpdgugODmzwu+OMS LmeVZGAdUBW7l7GzygghdDpLsz0oELPEdGv7JVw3JmP3iGheo/4T7jidFlKAypbciy 7bI+bsP27Yw9A== Received: from phl-compute-05.internal (phl-compute-05.internal [10.202.2.45]) by mailfauth.phl.internal (Postfix) with ESMTP id 5ED64F40068; Thu, 9 Jul 2026 19:57:32 -0400 (EDT) Received: from phl-frontend-04 ([10.202.2.163]) by phl-compute-05.internal (MEProxy); Thu, 09 Jul 2026 19:57:32 -0400 X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: dmFkZTFRjNBlnTz3PRsAmwjqRoF0mrjGm979SwqAKHEfthIBDq5uh/i9WRUkVW7VZSf//w YDoaw7hRG798DaAYdC6UbfhFGRdHF+jU+/jGu6HBle2Ytf+9RWyMwBDwRmckEaZLf/nUyQ SKi5sJRgbDjlp94ASRYw/4muCvkc2xHnl/vxqUx1y1DhspUjPMoJnbB/bl00rpb5PWiQyg GTtZWI4G6plLyhOdjNWH8CBGphBXLtH3D2Pvho0pAK+KnWiAORXsSOpMdV4xD7ID8QXYje a9mh9aiUSp78AdFrJ9O2B3vkzu06KG1gqyHdViPBwiRVrcIhbVPJi05ziCPPBR/N6vYfer 6lrpXziKcnjva9wT7p5QUwgxDdC5jjdwT7fXiZidMKAEs3vLpiGVt16GoilNTbBE1Swe66 lq1nYogPtBgSjvZCHT/YZLpCIqUO4TamHC1Gj5FtyOihURCc/3jiGGJS5HrnflvJVUhjxl uPu1tEET6rrY+yW5GgTNYjuDoKs+MzBD57qey3Z58xdp6wOjNRKNBRIG8N4BLdwR9dsmCv A4RIo/MDKkVvsbyt2hA+z7nruReU0o4mcD3lQXH5OqBkbo9AE/nGnLS1/bS/nnG97VTtRr clacuChAjPCOEchopHVZNuyYh3E0NUuVP+WPVNPQEQOSK3N74GMuftNUjPxA X-ME-Proxy: Feedback-ID: i67ae4b3e:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Thu, 9 Jul 2026 19:57:31 -0400 (EDT) Date: Thu, 09 Jul 2026 16:57:30 -0700 From: "Dan Williams (nvidia)" To: Gregory Price , "Dan Williams (nvidia)" Cc: linux-mm@kvack.org, nvdimm@lists.linux.dev, linux-kernel@vger.kernel.org, linux-cxl@vger.kernel.org, driver-core@lists.linux.dev, linux-kselftest@vger.kernel.org, kernel-team@meta.com, david@kernel.org, osalvador@suse.de, gregkh@linuxfoundation.org, rafael@kernel.org, dakr@kernel.org, vishal.l.verma@intel.com, dave.jiang@intel.com, alison.schofield@intel.com, akpm@linux-foundation.org, ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, shuah@kernel.org, iweiny@kernel.org, Smita.KoralahalliChannabasappa@amd.com, apopple@nvidia.com, Hannes Reinecke Message-ID: <6a50356aa7a4a_3cabcb1008a@djbw-dev.notmuch> In-Reply-To: References: <20260630211842.2252800-1-gourry@gourry.net> <20260630211842.2252800-10-gourry@gourry.net> <6a502267b17cc_3b7ee51008f@djbw-dev.notmuch> Subject: Re: [PATCH v6 09/10] dax/kmem: add sysfs interface for atomic whole-device hotplug Precedence: bulk X-Mailing-List: driver-core@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Gregory Price wrote: > > So the "unknown" case does not need to be here. > > > > mhp_online_type_to_str can technically return NULL, seems better to not > just let a NULL dereference sit latent even if we can visually tell it > can't happen today? Oh, makes sense I was thinking "unknown" was only a result of the drvdata missing case. > > > + if (dax_kmem_state_is_online(data->state)) { > > > + dev_warn(dev, "Hotplug regions stuck online until reboot\n"); > > > > I like that the BUG() is avoided, but I think these should stay > > dev_err() given the severity. > > > > I had to go back to calling remove_memory() by default given different > feedback, but I think if anything I will just modify the BUG() to a > WARN() and call it a day. ack.