From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx134.postini.com [74.125.245.134]) by kanga.kvack.org (Postfix) with SMTP id 779286B006E for ; Mon, 29 Oct 2012 10:12:11 -0400 (EDT) Message-ID: <1351519472.19172.84.camel@misato.fc.hp.com> Subject: Re: [PATCH v3 3/3] acpi,memory-hotplug : add memory offline code to acpi_memory_device_remove() From: Toshi Kani Date: Mon, 29 Oct 2012 08:04:32 -0600 In-Reply-To: <508E1F3D.7030806@cn.fujitsu.com> References: <1351247463-5653-1-git-send-email-wency@cn.fujitsu.com> <1351247463-5653-4-git-send-email-wency@cn.fujitsu.com> <1351271671.19172.74.camel@misato.fc.hp.com> <508E1F3D.7030806@cn.fujitsu.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Wen Congyang Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "linux-acpi@vger.kernel.org" , "liuj97@gmail.com" , "len.brown@intel.com" , "akpm@linux-foundation.org" , "kosaki.motohiro@jp.fujitsu.com" , "isimatu.yasuaki@jp.fujitsu.com" , "rjw@sisk.pl" , "laijs@cn.fujitsu.com" , David Rientjes , Christoph Lameter , Minchan Kim On Mon, 2012-10-29 at 06:16 +0000, Wen Congyang wrote: > At 10/27/2012 01:14 AM, Toshi Kani Wrote: > > On Fri, 2012-10-26 at 18:31 +0800, wency@cn.fujitsu.com wrote: > >> From: Yasuaki Ishimatsu > >> > >> The memory device can be removed by 2 ways: > >> 1. send eject request by SCI > >> 2. echo 1 >/sys/bus/pci/devices/PNP0C80:XX/eject > >> > >> In the 1st case, acpi_memory_disable_device() will be called. > >> In the 2nd case, acpi_memory_device_remove() will be called. > > > > Hi Yasuaki, Wen, > > > > Why do you need to have separate code design & implementation for the > > two cases? In other words, can the 1st case simply use the same code > > path of the 2nd case, just like I did for the CPU hot-remove patch > > below? It will simplify the code and make the memory notify handler > > more consistent with other handlers. > > https://lkml.org/lkml/2012/10/19/456 > > Yes, the 1st case can simply reuse the same code of the 2nd case. > It is another issue. The memory is not offlined and removed in 2nd > case. This patchset tries to fix this problem. After doing this, > we can merge the codes for the two cases. > > But there is some bug in the code for 2nd case: > If offlining memory failed, we don't know such error in 2nd case, and > the kernel will in a dangerous state: the memory device is poweroffed > but the kernel is using it. > > We should fix this bug before merging them. Hi Wen, Sounds good. Thanks for the clarification! -Toshi > Thanks > Wen Congyang > -- 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