Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756378Ab2JQI7o (ORCPT ); Wed, 17 Oct 2012 04:59:44 -0400 Received: from mail-oa0-f46.google.com ([209.85.219.46]:37382 "EHLO mail-oa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751908Ab2JQI7n (ORCPT ); Wed, 17 Oct 2012 04:59:43 -0400 MIME-Version: 1.0 In-Reply-To: <507E54AA.2080806@cn.fujitsu.com> References: <506C0AE8.40702@jp.fujitsu.com> <506C0C53.60205@jp.fujitsu.com> <50727984.20401@cn.fujitsu.com> <507E54AA.2080806@cn.fujitsu.com> From: KOSAKI Motohiro Date: Wed, 17 Oct 2012 04:59:22 -0400 X-Google-Sender-Auth: NSTnBjmG0GoCjB4hIs_Nh7hEx5s Message-ID: Subject: Re: [PATCH 1/4] acpi,memory-hotplug : add memory offline code to acpi_memory_device_remove() To: Wen Congyang Cc: Yasuaki Ishimatsu , 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 Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2358 Lines: 62 On Wed, Oct 17, 2012 at 2:48 AM, Wen Congyang wrote: > At 10/13/2012 03:10 AM, KOSAKI Motohiro Wrote: >>>>> -static int acpi_memory_disable_device(struct acpi_memory_device *mem_device) >>>>> +static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device) >>>>> { >>>>> int result; >>>>> struct acpi_memory_info *info, *n; >>>>> >>>>> + list_for_each_entry_safe(info, n, &mem_device->res_list, list) { >>>> >>>> Which lock protect this loop? >>> >>> There is no any lock to protect it now... >> >> When iterate an item removal list, you should use lock for protecting from >> memory corruption. >> >> >> >> >>>>> +static int acpi_memory_disable_device(struct acpi_memory_device *mem_device) >>>>> +{ >>>>> + int result; >>>>> >>>>> /* >>>>> * Ask the VM to offline this memory range. >>>>> * Note: Assume that this function returns zero on success >>>>> */ >>>> >>>> Write function comment instead of this silly comment. >>>> >>>>> - list_for_each_entry_safe(info, n, &mem_device->res_list, list) { >>>>> - if (info->enabled) { >>>>> - result = remove_memory(info->start_addr, info->length); >>>>> - if (result) >>>>> - return result; >>>>> - } >>>>> - kfree(info); >>>>> - } >>>>> + result = acpi_memory_remove_memory(mem_device); >>>>> + if (result) >>>>> + return result; >>>>> >>>>> /* Power-off and eject the device */ >>>>> result = acpi_memory_powerdown_device(mem_device); >>>> >>>> This patch move acpi_memory_powerdown_device() from ACPI_NOTIFY_EJECT_REQUEST >>>> to release callback, but don't explain why. >>> >>> Hmm, it doesn't move the code. It just reuse the code in acpi_memory_powerdown_device(). >> >> Even if reuse or not reuse, you changed the behavior. If any changes >> has no good rational, you cannot get an ack. > > I don't understand this? IIRC, the behavior isn't changed. Heh, please explain why do you think so. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/