From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yasuaki Ishimatsu Subject: Re: [PATCH 0/2] memory-hotplug : notification of memoty block's state Date: Tue, 2 Oct 2012 19:00:06 +0900 Message-ID: <506ABB26.3020806@jp.fujitsu.com> References: <506AA4E2.7070302@jp.fujitsu.com> <506AB719.70904@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-2022-JP" Content-Transfer-Encoding: 7bit Return-path: Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:58403 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751631Ab2JBKAm (ORCPT ); Tue, 2 Oct 2012 06:00:42 -0400 In-Reply-To: <506AB719.70904@gmail.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Ni zhan Chen Cc: x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, rientjes@google.com, liuj97@gmail.com, len.brown@intel.com, cl@linux.com, minchan.kim@gmail.com, akpm@linux-foundation.org, kosaki.motohiro@jp.fujitsu.com, wency@cn.fujitsu.com 2012/10/02 18:42, Ni zhan Chen wrote: > On 10/02/2012 04:25 PM, Yasuaki Ishimatsu wrote: >> We are trying to implement a physical memory hot removing function as >> following thread. >> >> https://lkml.org/lkml/2012/9/5/201 >> >> But there is not enough review to merge into linux kernel. >> >> I think there are following blockades. >> 1. no physical memory hot removable system >> 2. huge patch-set >> >> If you have a KVM system, we can get rid of 1st blockade. Because >> applying following patch, we can create memory hot removable system >> on KVM guest. >> >> http://lists.gnu.org/archive/html/qemu-devel/2012-07/msg01389.html >> >> 2nd blockade is own problem. So we try to divide huge patch into >> a small patch in each function as follows: >> >> - bug fix >> - acpi framework >> - kernel core >> >> We had already sent bug fix patches. >> >> https://lkml.org/lkml/2012/9/27/39 >> >> And the patch fixes following bug. >> >> remove_memory() offlines memory. And it is called by following two cases: >> >> 1. echo offline >/sys/devices/system/memory/memoryXX/state >> 2. hot remove a memory device >> >> In the 1st case, the memory block's state is changed and the notification >> that memory block's state changed is sent to userland after calling >> offline_memory(). So user can notice memory block is changed., > > Hi Yasuaki, > > Thanks for splitting the patchset, it's more easier to review this time. > One question: > > How can notify userspace? you mean function node_memory_callback or > ...., but When calling memory_block_change_state(), it calls kobject_uevent(). This function notifies userspace of the online/offline notification. Thanks, Yasuaki Ishimatsu > this function basically do nothing. > >> >> But in the 2nd case, the memory block's state is not changed and the >> notification is not also sent to userspcae even if calling offline_memory(). >> So user cannot notice memory block is changed. >> >> We should also notify to userspace at 2nd case. >> >> -- >> 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/ . >> Don't email: email@kvack.org >> > > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >