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 C80C51E47B4; Wed, 12 Feb 2025 07:49:45 +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=1739346586; cv=none; b=QwgML91EjDC0tyYP2cVENf2rGjK7jJwO/GVW/0R/mjc0OAFp2Kxr+oibu7LuA5cEpO5vFpTl7AsuntFAoHfJwm/ArufAiVmen8Q3dveJ6azFd7bz5AvBssclmFZ6jBBf7LM45BV8TihE9RyR6z6sDpMRL1IIxwC04Hl9rgIXhDc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739346586; c=relaxed/simple; bh=8w9Hl06CLUYgviD29yBA21KUXubpdXVQiG1IHZKXkeU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=R9a5ownmfuzfqTdGm9zBVKut1o1XGoPELdKY0zcuLyjpMkRzvnbNOGl4CVJzgeKttYz0o1F7AL8KKWHkwlge22tS+X0A7p2/TuBOLT/WeqxcaBTFyLwjGfP52zVsFN96CYEr5BBGsOgyxt3rpDWVGCGk2QxbGpBSk/1Kx70eKZY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=M3ExI9lE; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="M3ExI9lE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE33CC4CEDF; Wed, 12 Feb 2025 07:49:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1739346585; bh=8w9Hl06CLUYgviD29yBA21KUXubpdXVQiG1IHZKXkeU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=M3ExI9lEP6kCp7MpcbrMay2usPSFkRdmWF/MUCMp8sGF9f3fWOZnXOWGMhLG7Af0D XJhz7PicapucY+881T6fDxdoL4ZPfITHzynpULuGGN5btzaVwT1fvAax4+yQPlOEtS Jyo/nfqLV6EFHfklhlDcJvLylHlhg8IH70C8Y1Z4= Date: Wed, 12 Feb 2025 08:48:41 +0100 From: Greg Kroah-Hartman To: "Luck, Tony" Cc: "Moore, Robert" , "Wysocki, Rafael J" , Len Brown , "linux-acpi@vger.kernel.org" , "acpica-devel@lists.linux.dev" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "x86@kernel.org" , "H. Peter Anvin" , David Hildenbrand , Oscar Salvador , Danilo Krummrich , Andrew Morton , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 3/4] ACPI/MRRM: Add "node" symlink to /sys/devices/system/memory/rangeX Message-ID: <2025021231-panhandle-stonewall-ba3e@gregkh> References: <20250210211223.6139-1-tony.luck@intel.com> <20250210211223.6139-4-tony.luck@intel.com> <2025021111-deepen-landing-4252@gregkh> Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Feb 11, 2025 at 05:02:11PM +0000, Luck, Tony wrote: > >> + if (node) > >> + ret = sysfs_create_link(&entry->dev.kobj, &node->dev.kobj, "node"); > > > > What is going to remove this symlink if the memory goes away? Or do > > these never get removed? > > There's currently no method for runtime changes to these memory ranges. They > are described by a static ACPI table. I need to poke the folks that came up > with this to ask how memory hotplug will be handled (since CXL seems to be > making that fashionable again). ACPI should be supporting memory hotplug today, at the very least "memory add", so surely you have some old boxes to test this with? > > symlinks in sysfs created like this always worry me. What is going to > > use it? > > User space tools that want to understand what the "per-region" > monitoring and control features are actually operating on. If you don't have a real user today, please don't include it now. Wait until it is actually needed. thanks, greg k-h