From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B40863B585C; Mon, 13 Apr 2026 15:23:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776093799; cv=none; b=s1+HvOTIOFLSiB332IrH8DHHUh6dk8mtKjY0EI3tTd2aJppHwZCx2qPq1zTvCQrfLMzWJhd33373W9eWcBLoukRn7x8NUEknBbXlGBgXDMGpNlSVpol0wjhLgETHUFqPQSseOpQ2fF9jPOz4yUNIELh5kuW4RDJxf84R0eiIGKs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776093799; c=relaxed/simple; bh=S45XMgptda56IsZAs7DVd5a3LNMAqRWpvRwu+DHIPGQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ps1TgRLS1sRujfc/1enmdtuOeRzFN3bFEV0j8MNWDqg1mr8JVZfOXpUiYG/vnRf9FtMwJCNopmzzLghNIzq7Uu4vrpi6ezZ9EHJQV+Rc9xqTex2F0u+lh0TpLYX3Ok2crdsPYzYTepbnDAcQ9kkZhzb91t4X+GmzNkqEtFjiDZk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BYE59FG1; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="BYE59FG1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 28BDEC2BCB0; Mon, 13 Apr 2026 15:23:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776093799; bh=S45XMgptda56IsZAs7DVd5a3LNMAqRWpvRwu+DHIPGQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=BYE59FG1YQ0pT8LVUF+tv5zY7dYAb5xA9h6J7NT7HBj1dnAg7HpvrDCSEqlonD57R 8HpbASIbg3q2rlDrHvQFz4aruyuJhmFLSxnSEFDPXQ0Vqbu8Q54XmzXM4D75mnM0JZ zOwruWwCr4X7vE07w18nFeU25jDCX/DuSX2K+fg0Pi6bBenTPwbEPpLhrbHaL0OZ1t pYUoSRvSbdhax38dFAUgo4xR+x2eGlzUFsw0qE5DkqmJhu3MoMoAODwwQ+8wXPbsl9 +V+Q0rzeYQnoRWRQKcKIfBJd+9XzRZ9seOmCt2SmRaAzZfTCNPl5iZosMNoZ8dmXrB OBn7uKUVLvJXQ== Message-ID: <3a4166db-fd04-4a9a-a25a-a7b6d149b97f@kernel.org> Date: Mon, 13 Apr 2026 17:23:11 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 6/8] dax: plumb hotplug online_type through dax To: Gregory Price , linux-mm@kvack.org, vishal.l.verma@intel.com, dave.jiang@intel.com, akpm@linux-foundation.org, osalvador@suse.de Cc: dan.j.williams@intel.com, ljs@kernel.org, Liam.Howlett@oracle.com, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, linux-kernel@vger.kernel.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, kernel-team@meta.com References: <20260321150404.3288786-1-gourry@gourry.net> <20260321150404.3288786-7-gourry@gourry.net> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/21/26 16:04, Gregory Price wrote: > There is no way for drivers leveraging dax_kmem to plumb through a > preferred auto-online policy - the system default policy is forced. > > Add 'enum mmop' field to DAX device creation path to allow drivers > to specify an auto-online policy when using the kmem driver. > > Current callers initialize online_type to mhp_get_default_online_type() > to retain backward compatibility and to make explicit to the drivers > what is actually happening underneath. > > No functional changes to existing callers. > > Cc:David Hildenbrand > Signed-off-by: Gregory Price > --- [...] > > return PTR_ERR_OR_ZERO(devm_create_dev_dax(&data)); > diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c > index 798f389df992..d4c34b2e3766 100644 > --- a/drivers/dax/kmem.c > +++ b/drivers/dax/kmem.c > @@ -16,6 +16,11 @@ > #include "dax-private.h" > #include "bus.h" > > +/* Internal function exported only to kmem module */ > +extern int __add_memory_driver_managed(int nid, u64 start, u64 size, > + const char *resource_name, > + mhp_t mhp_flags, enum mmop online_type); This should just go to the memory_hotplug.h header. The EXPORT will make sure that only supported modules can use this. > + > /* Memory resource name used for add_memory_driver_managed(). */ > static const char *kmem_name; > /* Set if any memory will remain added when the driver will be unloaded. */ > @@ -49,6 +54,7 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax) > struct dax_kmem_data *data; > struct memory_dev_type *mtype; > int i, rc, mapped = 0; > + enum mmop online_type; > mhp_t mhp_flags; > int numa_node; > int adist = MEMTIER_DEFAULT_LOWTIER_ADISTANCE; > @@ -111,6 +117,8 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax) > goto err_reg_mgid; > data->mgid = rc; > > + online_type = dev_dax->online_type; Do you need the temporary variable? -- Cheers, David