From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wen Congyang Subject: Re: enabled and failed flags in acpi_memory_info Date: Wed, 16 Jan 2013 22:33:13 +0800 Message-ID: <50F6BA29.9020201@cn.fujitsu.com> References: <1357693472.14145.42.camel@misato.fc.hp.com> <1358197617.14145.92.camel@misato.fc.hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from cn.fujitsu.com ([222.73.24.84]:60832 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1750963Ab3APO0B (ORCPT ); Wed, 16 Jan 2013 09:26:01 -0500 In-Reply-To: <1358197617.14145.92.camel@misato.fc.hp.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Toshi Kani Cc: isimatu.yasuaki@jp.fujitsu.com, linux-acpi@vger.kernel.org Sorry for late reply. At 01/15/2013 05:06 AM, Toshi Kani Wrote: > Wen, Yasuaki, any thoughts on this? > > Thanks, > -Toshi > > > On Tue, 2013-01-08 at 18:04 -0700, Toshi Kani wrote: >> Hi Wen, >> >> I have a question about the change you made in commit 65479472 in >> acpi_memhotplug.c. This change seems to require that >> acpi_memory_enable_device() calls add_memory() to add all memory ranges >> represented by memory device objects at boot-time, and keep the results >> be used for hot-remove. >> >> If I understand it right, this add_memory() call fails with EEXIST at >> boot-time since all memory ranges should have been added from EFI memory >> table (or e820) already. This results all memory ranges be marked as ! >> enabled & !failed. I think this means that we cannot hot-delete any >> memory ranges presented at boot-time since acpi_memory_remove_memory() >> only calls remove_memory() when the enabled flag is set. Is that >> correct? If so, why do we need such restriction?t Hmm, it means that this memory range is not managed by this driver. I am not sure it is safe to remove it, so I restrict it... If it is safe to remove such memory, you can remove this restriction. Thanks Wen Congyang >> >> In addition, as part of RFC patchset of proposed hotplug framework below >> (well, this is why I am wondering this... :), I simply called >> add_memory() and remove_memory() for the ranges requested for hot-add / >> hot-delete. It does not call add_memory() at boot-time and set the >> enabled & failed flags. But it does not eject memory when >> remove_memory() failed, either. Do you see any problems with this >> approach? >> https://lkml.org/lkml/2012/12/12/457 >> >> Thanks, >> -Toshi > > >