From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with SMTP id 053FC8D000E for ; Wed, 1 Dec 2010 21:35:34 -0500 (EST) From: "Zheng, Shaohui" Date: Thu, 2 Dec 2010 10:35:00 +0800 Subject: RE: [8/8, v6] NUMA Hotplug Emulator: implement debugfs interface for memory probe Message-ID: References: <20101202002716.GA13693@shaohui> In-Reply-To: Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org To: David Rientjes Cc: Andrew Morton , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "lethal@linux-sh.org" , Andi Kleen , Dave Hansen , Greg KH , "Li, Haicheng" , "shaohui.zheng@linux.intel.com" List-ID: Why should we add so many interfaces for memory hotplug emulation? If so, w= e should create both sysfs and debugfs=20 entries for an online node, we are trying to add redundant code logic. We need not make a simple thing such complicated, Simple is beautiful, I'd = prefer to rename the mem_hotplug/probe=20 interface as mem_hotplug/add_memory. /sys/kernel/debug/mem_hotplug/add_node (already exists) /sys/kernel/debug/mem_hotplug/add_memory (rename probe as add_memory) Thanks & Regards, Shaohui -----Original Message----- From: David Rientjes [mailto:rientjes@google.com]=20 Sent: Thursday, December 02, 2010 10:13 AM To: Zheng, Shaohui Cc: Andrew Morton; linux-mm@kvack.org; linux-kernel@vger.kernel.org; lethal= @linux-sh.org; Andi Kleen; Dave Hansen; Greg KH; Li, Haicheng Subject: Re: [8/8, v6] NUMA Hotplug Emulator: implement debugfs interface f= or memory probe On Thu, 2 Dec 2010, Shaohui Zheng wrote: > so we should still keep the sysfs memory/probe interface without any modi= fications, > but for the debugfs mem_hotplug/probe interface, we can add the memory re= gion=20 > to a desired node. This feature would be distinct from the add_node interface already=20 provided: instead of hotplugging a new node to test the memory hotplug=20 callbacks, this new interface would only be hotadding new memory to a node= =20 other than the one it has physical affinity with. For that support, I'd=20 suggest new probe files in debugfs for each online node: /sys/kernel/debug/mem_hotplug/add_node (already exists) /sys/kernel/debug/mem_hotplug/node0/add_memory /sys/kernel/debug/mem_hotplug/node1/add_memory ... and then you can offline and remove that memory with the existing hotplug=20 support (CONFIG_MEMORY_HOTPLUG and CONFIG_MEMORY_HOTREMOVE, respectively). -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org