From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yasuaki Ishimatsu Subject: Re: [RFC PATCH v3 2/13] memory-hotplug : add physical memory hotplug code to acpi_memory_device_remove Date: Tue, 17 Jul 2012 10:44:59 +0900 Message-ID: <5004C39B.1060204@jp.fujitsu.com> References: <4FFAB0A2.8070304@jp.fujitsu.com> <4FFAB148.9000803@jp.fujitsu.com> <4FFF9771.5080307@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-2022-JP" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4FFF9771.5080307@cn.fujitsu.com> Sender: owner-linux-mm@kvack.org To: Wen Congyang Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, rientjes@google.com, liuj97@gmail.com, len.brown@intel.com, benh@kernel.crashing.org, paulus@samba.org, cl@linux.com, minchan.kim@gmail.com, akpm@linux-foundation.org, kosaki.motohiro@jp.fujitsu.com List-Id: linux-acpi@vger.kernel.org Hi Wen, 2012/07/13 12:35, Wen Congyang wrote: > At 07/09/2012 06:24 PM, Yasuaki Ishimatsu Wrote: >> acpi_memory_device_remove() has been prepared to remove physical memory. >> But, the function only frees acpi_memory_device currentlry. >> >> The patch adds following functions into acpi_memory_device_remove(): >> - offline memory >> - remove physical memory (only return -EBUSY) >> - free acpi_memory_device >> >> CC: David Rientjes >> CC: Jiang Liu >> CC: Len Brown >> CC: Benjamin Herrenschmidt >> CC: Paul Mackerras >> CC: Christoph Lameter >> Cc: Minchan Kim >> CC: Andrew Morton >> CC: KOSAKI Motohiro >> CC: Wen Congyang >> Signed-off-by: Yasuaki Ishimatsu >> >> --- >> drivers/acpi/acpi_memhotplug.c | 26 +++++++++++++++++++++++++- >> drivers/base/memory.c | 39 +++++++++++++++++++++++++++++++++++++++ >> include/linux/memory.h | 5 +++++ >> include/linux/memory_hotplug.h | 1 + >> mm/memory_hotplug.c | 8 ++++++++ >> 5 files changed, 78 insertions(+), 1 deletion(-) >> >> Index: linux-3.5-rc6/drivers/acpi/acpi_memhotplug.c >> =================================================================== >> --- linux-3.5-rc6.orig/drivers/acpi/acpi_memhotplug.c 2012-07-09 18:08:29.946888653 +0900 >> +++ linux-3.5-rc6/drivers/acpi/acpi_memhotplug.c 2012-07-09 18:08:43.470719531 +0900 >> @@ -29,6 +29,7 @@ >> #include >> #include >> #include >> +#include >> #include >> #include >> #include >> @@ -452,12 +453,35 @@ static int acpi_memory_device_add(struct >> static int acpi_memory_device_remove(struct acpi_device *device, int type) >> { >> struct acpi_memory_device *mem_device = NULL; >> - >> + struct acpi_memory_info *info, *tmp; >> + int result; >> + int node; >> >> if (!device || !acpi_driver_data(device)) >> return -EINVAL; >> >> mem_device = acpi_driver_data(device); >> + >> + node = acpi_get_node(mem_device->device->handle); >> + >> + list_for_each_entry_safe(info, tmp, &mem_device->res_list, list) { >> + if (!info->enabled) >> + continue; >> + >> + if (!is_memblk_offline(info->start_addr, info->length)) { >> + result = offline_memory(info->start_addr, info->length); >> + if (result) >> + return result; >> + } >> + >> + result = remove_memory(node, info->start_addr, info->length); > > The user may online the memory between offline_memory() and remove_memory(). > So I think we should lock memory hotplug before check the memory's status > and release it after remove_memory(). How about get "mem_block->state_mutex" of removed memory? When offlining memory, we need to change "memory_block->state" into "MEM_OFFLINE". In this case, we get mem_block->state_mutex. So I think the mutex lock is beneficial. Thanks, Yasuaki Ishimatsu > > Thanks > Wen Congyang > >> + if (result) >> + return result; >> + >> + list_del(&info->list); >> + kfree(info); >> + } >> + >> kfree(mem_device); >> >> return 0; >> Index: linux-3.5-rc6/include/linux/memory_hotplug.h >> =================================================================== >> --- linux-3.5-rc6.orig/include/linux/memory_hotplug.h 2012-07-09 18:08:29.955888542 +0900 >> +++ linux-3.5-rc6/include/linux/memory_hotplug.h 2012-07-09 18:08:43.471719518 +0900 >> @@ -233,6 +233,7 @@ static inline int is_mem_section_removab >> extern int mem_online_node(int nid); >> extern int add_memory(int nid, u64 start, u64 size); >> extern int arch_add_memory(int nid, u64 start, u64 size); >> +extern int remove_memory(int nid, u64 start, u64 size); >> extern int offline_memory(u64 start, u64 size); >> extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn, >> int nr_pages); >> Index: linux-3.5-rc6/mm/memory_hotplug.c >> =================================================================== >> --- linux-3.5-rc6.orig/mm/memory_hotplug.c 2012-07-09 18:08:29.953888567 +0900 >> +++ linux-3.5-rc6/mm/memory_hotplug.c 2012-07-09 18:08:43.476719455 +0900 >> @@ -659,6 +659,14 @@ out: >> } >> EXPORT_SYMBOL_GPL(add_memory); >> >> +int remove_memory(int nid, u64 start, u64 size) >> +{ >> + return -EBUSY; >> + >> +} >> +EXPORT_SYMBOL_GPL(remove_memory); >> + >> + >> #ifdef CONFIG_MEMORY_HOTREMOVE >> /* >> * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy >> Index: linux-3.5-rc6/drivers/base/memory.c >> =================================================================== >> --- linux-3.5-rc6.orig/drivers/base/memory.c 2012-07-09 18:08:29.947888640 +0900 >> +++ linux-3.5-rc6/drivers/base/memory.c 2012-07-09 18:10:54.880076739 +0900 >> @@ -70,6 +70,45 @@ void unregister_memory_isolate_notifier( >> } >> EXPORT_SYMBOL(unregister_memory_isolate_notifier); >> >> +bool is_memblk_offline(unsigned long start, unsigned long size) >> +{ >> + struct memory_block *mem = NULL; >> + struct mem_section *section; >> + unsigned long start_pfn, end_pfn; >> + unsigned long pfn, section_nr; >> + >> + start_pfn = PFN_DOWN(start); >> + end_pfn = start_pfn + PFN_DOWN(start); >> + >> + for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { >> + section_nr = pfn_to_section_nr(pfn); >> + if (!present_section_nr(section_nr)); >> + continue; >> + >> + section = __nr_to_section(section_nr); >> + /* same memblock? */ >> + if (mem) >> + if((section_nr >= mem->start_section_nr) && >> + (section_nr <= mem->end_section_nr)) >> + continue; >> + >> + mem = find_memory_block_hinted(section, mem); >> + if (!mem) >> + continue; >> + if (mem->state == MEM_OFFLINE) >> + continue; >> + >> + kobject_put(&mem->dev.kobj); >> + return false; >> + } >> + >> + if (mem) >> + kobject_put(&mem->dev.kobj); >> + >> + return true; >> +} >> +EXPORT_SYMBOL(is_memblk_offline); >> + >> /* >> * register_memory - Setup a sysfs device for a memory block >> */ >> Index: linux-3.5-rc6/include/linux/memory.h >> =================================================================== >> --- linux-3.5-rc6.orig/include/linux/memory.h 2012-07-08 09:23:56.000000000 +0900 >> +++ linux-3.5-rc6/include/linux/memory.h 2012-07-09 18:08:43.484719355 +0900 >> @@ -106,6 +106,10 @@ static inline int memory_isolate_notify( >> { >> return 0; >> } >> +static inline bool is_memblk_offline(unsigned long start, unsigned long size) >> +{ >> + return false; >> +} >> #else >> extern int register_memory_notifier(struct notifier_block *nb); >> extern void unregister_memory_notifier(struct notifier_block *nb); >> @@ -120,6 +124,7 @@ extern int memory_isolate_notify(unsigne >> extern struct memory_block *find_memory_block_hinted(struct mem_section *, >> struct memory_block *); >> extern struct memory_block *find_memory_block(struct mem_section *); >> +extern bool is_memblk_offline(unsigned long start, unsigned long size); >> #define CONFIG_MEM_BLOCK_SIZE (PAGES_PER_SECTION<> enum mem_add_context { BOOT, HOTPLUG }; >> #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ >> >> > > -- > 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, 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754095Ab2GQBpZ (ORCPT ); Mon, 16 Jul 2012 21:45:25 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:38630 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750906Ab2GQBpW (ORCPT ); Mon, 16 Jul 2012 21:45:22 -0400 X-SecurityPolicyCheck: OK by SHieldMailChecker v1.7.4 Message-ID: <5004C39B.1060204@jp.fujitsu.com> Date: Tue, 17 Jul 2012 10:44:59 +0900 From: Yasuaki Ishimatsu User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: Wen Congyang CC: , , , , , , , , , , , , Subject: Re: [RFC PATCH v3 2/13] memory-hotplug : add physical memory hotplug code to acpi_memory_device_remove References: <4FFAB0A2.8070304@jp.fujitsu.com> <4FFAB148.9000803@jp.fujitsu.com> <4FFF9771.5080307@cn.fujitsu.com> In-Reply-To: <4FFF9771.5080307@cn.fujitsu.com> Content-Type: text/plain; charset="ISO-2022-JP" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Wen, 2012/07/13 12:35, Wen Congyang wrote: > At 07/09/2012 06:24 PM, Yasuaki Ishimatsu Wrote: >> acpi_memory_device_remove() has been prepared to remove physical memory. >> But, the function only frees acpi_memory_device currentlry. >> >> The patch adds following functions into acpi_memory_device_remove(): >> - offline memory >> - remove physical memory (only return -EBUSY) >> - free acpi_memory_device >> >> CC: David Rientjes >> CC: Jiang Liu >> CC: Len Brown >> CC: Benjamin Herrenschmidt >> CC: Paul Mackerras >> CC: Christoph Lameter >> Cc: Minchan Kim >> CC: Andrew Morton >> CC: KOSAKI Motohiro >> CC: Wen Congyang >> Signed-off-by: Yasuaki Ishimatsu >> >> --- >> drivers/acpi/acpi_memhotplug.c | 26 +++++++++++++++++++++++++- >> drivers/base/memory.c | 39 +++++++++++++++++++++++++++++++++++++++ >> include/linux/memory.h | 5 +++++ >> include/linux/memory_hotplug.h | 1 + >> mm/memory_hotplug.c | 8 ++++++++ >> 5 files changed, 78 insertions(+), 1 deletion(-) >> >> Index: linux-3.5-rc6/drivers/acpi/acpi_memhotplug.c >> =================================================================== >> --- linux-3.5-rc6.orig/drivers/acpi/acpi_memhotplug.c 2012-07-09 18:08:29.946888653 +0900 >> +++ linux-3.5-rc6/drivers/acpi/acpi_memhotplug.c 2012-07-09 18:08:43.470719531 +0900 >> @@ -29,6 +29,7 @@ >> #include >> #include >> #include >> +#include >> #include >> #include >> #include >> @@ -452,12 +453,35 @@ static int acpi_memory_device_add(struct >> static int acpi_memory_device_remove(struct acpi_device *device, int type) >> { >> struct acpi_memory_device *mem_device = NULL; >> - >> + struct acpi_memory_info *info, *tmp; >> + int result; >> + int node; >> >> if (!device || !acpi_driver_data(device)) >> return -EINVAL; >> >> mem_device = acpi_driver_data(device); >> + >> + node = acpi_get_node(mem_device->device->handle); >> + >> + list_for_each_entry_safe(info, tmp, &mem_device->res_list, list) { >> + if (!info->enabled) >> + continue; >> + >> + if (!is_memblk_offline(info->start_addr, info->length)) { >> + result = offline_memory(info->start_addr, info->length); >> + if (result) >> + return result; >> + } >> + >> + result = remove_memory(node, info->start_addr, info->length); > > The user may online the memory between offline_memory() and remove_memory(). > So I think we should lock memory hotplug before check the memory's status > and release it after remove_memory(). How about get "mem_block->state_mutex" of removed memory? When offlining memory, we need to change "memory_block->state" into "MEM_OFFLINE". In this case, we get mem_block->state_mutex. So I think the mutex lock is beneficial. Thanks, Yasuaki Ishimatsu > > Thanks > Wen Congyang > >> + if (result) >> + return result; >> + >> + list_del(&info->list); >> + kfree(info); >> + } >> + >> kfree(mem_device); >> >> return 0; >> Index: linux-3.5-rc6/include/linux/memory_hotplug.h >> =================================================================== >> --- linux-3.5-rc6.orig/include/linux/memory_hotplug.h 2012-07-09 18:08:29.955888542 +0900 >> +++ linux-3.5-rc6/include/linux/memory_hotplug.h 2012-07-09 18:08:43.471719518 +0900 >> @@ -233,6 +233,7 @@ static inline int is_mem_section_removab >> extern int mem_online_node(int nid); >> extern int add_memory(int nid, u64 start, u64 size); >> extern int arch_add_memory(int nid, u64 start, u64 size); >> +extern int remove_memory(int nid, u64 start, u64 size); >> extern int offline_memory(u64 start, u64 size); >> extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn, >> int nr_pages); >> Index: linux-3.5-rc6/mm/memory_hotplug.c >> =================================================================== >> --- linux-3.5-rc6.orig/mm/memory_hotplug.c 2012-07-09 18:08:29.953888567 +0900 >> +++ linux-3.5-rc6/mm/memory_hotplug.c 2012-07-09 18:08:43.476719455 +0900 >> @@ -659,6 +659,14 @@ out: >> } >> EXPORT_SYMBOL_GPL(add_memory); >> >> +int remove_memory(int nid, u64 start, u64 size) >> +{ >> + return -EBUSY; >> + >> +} >> +EXPORT_SYMBOL_GPL(remove_memory); >> + >> + >> #ifdef CONFIG_MEMORY_HOTREMOVE >> /* >> * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy >> Index: linux-3.5-rc6/drivers/base/memory.c >> =================================================================== >> --- linux-3.5-rc6.orig/drivers/base/memory.c 2012-07-09 18:08:29.947888640 +0900 >> +++ linux-3.5-rc6/drivers/base/memory.c 2012-07-09 18:10:54.880076739 +0900 >> @@ -70,6 +70,45 @@ void unregister_memory_isolate_notifier( >> } >> EXPORT_SYMBOL(unregister_memory_isolate_notifier); >> >> +bool is_memblk_offline(unsigned long start, unsigned long size) >> +{ >> + struct memory_block *mem = NULL; >> + struct mem_section *section; >> + unsigned long start_pfn, end_pfn; >> + unsigned long pfn, section_nr; >> + >> + start_pfn = PFN_DOWN(start); >> + end_pfn = start_pfn + PFN_DOWN(start); >> + >> + for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { >> + section_nr = pfn_to_section_nr(pfn); >> + if (!present_section_nr(section_nr)); >> + continue; >> + >> + section = __nr_to_section(section_nr); >> + /* same memblock? */ >> + if (mem) >> + if((section_nr >= mem->start_section_nr) && >> + (section_nr <= mem->end_section_nr)) >> + continue; >> + >> + mem = find_memory_block_hinted(section, mem); >> + if (!mem) >> + continue; >> + if (mem->state == MEM_OFFLINE) >> + continue; >> + >> + kobject_put(&mem->dev.kobj); >> + return false; >> + } >> + >> + if (mem) >> + kobject_put(&mem->dev.kobj); >> + >> + return true; >> +} >> +EXPORT_SYMBOL(is_memblk_offline); >> + >> /* >> * register_memory - Setup a sysfs device for a memory block >> */ >> Index: linux-3.5-rc6/include/linux/memory.h >> =================================================================== >> --- linux-3.5-rc6.orig/include/linux/memory.h 2012-07-08 09:23:56.000000000 +0900 >> +++ linux-3.5-rc6/include/linux/memory.h 2012-07-09 18:08:43.484719355 +0900 >> @@ -106,6 +106,10 @@ static inline int memory_isolate_notify( >> { >> return 0; >> } >> +static inline bool is_memblk_offline(unsigned long start, unsigned long size) >> +{ >> + return false; >> +} >> #else >> extern int register_memory_notifier(struct notifier_block *nb); >> extern void unregister_memory_notifier(struct notifier_block *nb); >> @@ -120,6 +124,7 @@ extern int memory_isolate_notify(unsigne >> extern struct memory_block *find_memory_block_hinted(struct mem_section *, >> struct memory_block *); >> extern struct memory_block *find_memory_block(struct mem_section *); >> +extern bool is_memblk_offline(unsigned long start, unsigned long size); >> #define CONFIG_MEM_BLOCK_SIZE (PAGES_PER_SECTION<> enum mem_add_context { BOOT, HOTPLUG }; >> #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ >> >> > > -- > 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 > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from fgwmail5.fujitsu.co.jp (fgwmail5.fujitsu.co.jp [192.51.44.35]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 832C02C0152 for ; Tue, 17 Jul 2012 11:45:22 +1000 (EST) Received: from m1.gw.fujitsu.co.jp (unknown [10.0.50.71]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id 27BEF3EE0BD for ; Tue, 17 Jul 2012 10:45:18 +0900 (JST) Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 0DCA145DE5C for ; Tue, 17 Jul 2012 10:45:18 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id E9D5A45DE56 for ; Tue, 17 Jul 2012 10:45:17 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id D37C51DB8055 for ; Tue, 17 Jul 2012 10:45:17 +0900 (JST) Received: from g01jpexchyt01.g01.fujitsu.local (g01jpexchyt01.g01.fujitsu.local [10.128.194.40]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 7AE8D1DB8052 for ; Tue, 17 Jul 2012 10:45:17 +0900 (JST) Message-ID: <5004C39B.1060204@jp.fujitsu.com> Date: Tue, 17 Jul 2012 10:44:59 +0900 From: Yasuaki Ishimatsu MIME-Version: 1.0 To: Wen Congyang Subject: Re: [RFC PATCH v3 2/13] memory-hotplug : add physical memory hotplug code to acpi_memory_device_remove References: <4FFAB0A2.8070304@jp.fujitsu.com> <4FFAB148.9000803@jp.fujitsu.com> <4FFF9771.5080307@cn.fujitsu.com> In-Reply-To: <4FFF9771.5080307@cn.fujitsu.com> Content-Type: text/plain; charset="ISO-2022-JP" Cc: len.brown@intel.com, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, paulus@samba.org, minchan.kim@gmail.com, kosaki.motohiro@jp.fujitsu.com, rientjes@google.com, cl@linux.com, linuxppc-dev@lists.ozlabs.org, akpm@linux-foundation.org, liuj97@gmail.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi Wen, 2012/07/13 12:35, Wen Congyang wrote: > At 07/09/2012 06:24 PM, Yasuaki Ishimatsu Wrote: >> acpi_memory_device_remove() has been prepared to remove physical memory. >> But, the function only frees acpi_memory_device currentlry. >> >> The patch adds following functions into acpi_memory_device_remove(): >> - offline memory >> - remove physical memory (only return -EBUSY) >> - free acpi_memory_device >> >> CC: David Rientjes >> CC: Jiang Liu >> CC: Len Brown >> CC: Benjamin Herrenschmidt >> CC: Paul Mackerras >> CC: Christoph Lameter >> Cc: Minchan Kim >> CC: Andrew Morton >> CC: KOSAKI Motohiro >> CC: Wen Congyang >> Signed-off-by: Yasuaki Ishimatsu >> >> --- >> drivers/acpi/acpi_memhotplug.c | 26 +++++++++++++++++++++++++- >> drivers/base/memory.c | 39 +++++++++++++++++++++++++++++++++++++++ >> include/linux/memory.h | 5 +++++ >> include/linux/memory_hotplug.h | 1 + >> mm/memory_hotplug.c | 8 ++++++++ >> 5 files changed, 78 insertions(+), 1 deletion(-) >> >> Index: linux-3.5-rc6/drivers/acpi/acpi_memhotplug.c >> =================================================================== >> --- linux-3.5-rc6.orig/drivers/acpi/acpi_memhotplug.c 2012-07-09 18:08:29.946888653 +0900 >> +++ linux-3.5-rc6/drivers/acpi/acpi_memhotplug.c 2012-07-09 18:08:43.470719531 +0900 >> @@ -29,6 +29,7 @@ >> #include >> #include >> #include >> +#include >> #include >> #include >> #include >> @@ -452,12 +453,35 @@ static int acpi_memory_device_add(struct >> static int acpi_memory_device_remove(struct acpi_device *device, int type) >> { >> struct acpi_memory_device *mem_device = NULL; >> - >> + struct acpi_memory_info *info, *tmp; >> + int result; >> + int node; >> >> if (!device || !acpi_driver_data(device)) >> return -EINVAL; >> >> mem_device = acpi_driver_data(device); >> + >> + node = acpi_get_node(mem_device->device->handle); >> + >> + list_for_each_entry_safe(info, tmp, &mem_device->res_list, list) { >> + if (!info->enabled) >> + continue; >> + >> + if (!is_memblk_offline(info->start_addr, info->length)) { >> + result = offline_memory(info->start_addr, info->length); >> + if (result) >> + return result; >> + } >> + >> + result = remove_memory(node, info->start_addr, info->length); > > The user may online the memory between offline_memory() and remove_memory(). > So I think we should lock memory hotplug before check the memory's status > and release it after remove_memory(). How about get "mem_block->state_mutex" of removed memory? When offlining memory, we need to change "memory_block->state" into "MEM_OFFLINE". In this case, we get mem_block->state_mutex. So I think the mutex lock is beneficial. Thanks, Yasuaki Ishimatsu > > Thanks > Wen Congyang > >> + if (result) >> + return result; >> + >> + list_del(&info->list); >> + kfree(info); >> + } >> + >> kfree(mem_device); >> >> return 0; >> Index: linux-3.5-rc6/include/linux/memory_hotplug.h >> =================================================================== >> --- linux-3.5-rc6.orig/include/linux/memory_hotplug.h 2012-07-09 18:08:29.955888542 +0900 >> +++ linux-3.5-rc6/include/linux/memory_hotplug.h 2012-07-09 18:08:43.471719518 +0900 >> @@ -233,6 +233,7 @@ static inline int is_mem_section_removab >> extern int mem_online_node(int nid); >> extern int add_memory(int nid, u64 start, u64 size); >> extern int arch_add_memory(int nid, u64 start, u64 size); >> +extern int remove_memory(int nid, u64 start, u64 size); >> extern int offline_memory(u64 start, u64 size); >> extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn, >> int nr_pages); >> Index: linux-3.5-rc6/mm/memory_hotplug.c >> =================================================================== >> --- linux-3.5-rc6.orig/mm/memory_hotplug.c 2012-07-09 18:08:29.953888567 +0900 >> +++ linux-3.5-rc6/mm/memory_hotplug.c 2012-07-09 18:08:43.476719455 +0900 >> @@ -659,6 +659,14 @@ out: >> } >> EXPORT_SYMBOL_GPL(add_memory); >> >> +int remove_memory(int nid, u64 start, u64 size) >> +{ >> + return -EBUSY; >> + >> +} >> +EXPORT_SYMBOL_GPL(remove_memory); >> + >> + >> #ifdef CONFIG_MEMORY_HOTREMOVE >> /* >> * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy >> Index: linux-3.5-rc6/drivers/base/memory.c >> =================================================================== >> --- linux-3.5-rc6.orig/drivers/base/memory.c 2012-07-09 18:08:29.947888640 +0900 >> +++ linux-3.5-rc6/drivers/base/memory.c 2012-07-09 18:10:54.880076739 +0900 >> @@ -70,6 +70,45 @@ void unregister_memory_isolate_notifier( >> } >> EXPORT_SYMBOL(unregister_memory_isolate_notifier); >> >> +bool is_memblk_offline(unsigned long start, unsigned long size) >> +{ >> + struct memory_block *mem = NULL; >> + struct mem_section *section; >> + unsigned long start_pfn, end_pfn; >> + unsigned long pfn, section_nr; >> + >> + start_pfn = PFN_DOWN(start); >> + end_pfn = start_pfn + PFN_DOWN(start); >> + >> + for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { >> + section_nr = pfn_to_section_nr(pfn); >> + if (!present_section_nr(section_nr)); >> + continue; >> + >> + section = __nr_to_section(section_nr); >> + /* same memblock? */ >> + if (mem) >> + if((section_nr >= mem->start_section_nr) && >> + (section_nr <= mem->end_section_nr)) >> + continue; >> + >> + mem = find_memory_block_hinted(section, mem); >> + if (!mem) >> + continue; >> + if (mem->state == MEM_OFFLINE) >> + continue; >> + >> + kobject_put(&mem->dev.kobj); >> + return false; >> + } >> + >> + if (mem) >> + kobject_put(&mem->dev.kobj); >> + >> + return true; >> +} >> +EXPORT_SYMBOL(is_memblk_offline); >> + >> /* >> * register_memory - Setup a sysfs device for a memory block >> */ >> Index: linux-3.5-rc6/include/linux/memory.h >> =================================================================== >> --- linux-3.5-rc6.orig/include/linux/memory.h 2012-07-08 09:23:56.000000000 +0900 >> +++ linux-3.5-rc6/include/linux/memory.h 2012-07-09 18:08:43.484719355 +0900 >> @@ -106,6 +106,10 @@ static inline int memory_isolate_notify( >> { >> return 0; >> } >> +static inline bool is_memblk_offline(unsigned long start, unsigned long size) >> +{ >> + return false; >> +} >> #else >> extern int register_memory_notifier(struct notifier_block *nb); >> extern void unregister_memory_notifier(struct notifier_block *nb); >> @@ -120,6 +124,7 @@ extern int memory_isolate_notify(unsigne >> extern struct memory_block *find_memory_block_hinted(struct mem_section *, >> struct memory_block *); >> extern struct memory_block *find_memory_block(struct mem_section *); >> +extern bool is_memblk_offline(unsigned long start, unsigned long size); >> #define CONFIG_MEM_BLOCK_SIZE (PAGES_PER_SECTION<> enum mem_add_context { BOOT, HOTPLUG }; >> #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ >> >> > > -- > 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 >