From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx199.postini.com [74.125.245.199]) by kanga.kvack.org (Postfix) with SMTP id 769B96B005A for ; Wed, 18 Jul 2012 06:51:34 -0400 (EDT) Received: from m1.gw.fujitsu.co.jp (unknown [10.0.50.71]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id 1353A3EE0B5 for ; Wed, 18 Jul 2012 19:51:33 +0900 (JST) Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id E6AC145DE5A for ; Wed, 18 Jul 2012 19:51:32 +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 D0CEC45DE56 for ; Wed, 18 Jul 2012 19:51:32 +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 C4EB4E38001 for ; Wed, 18 Jul 2012 19:51:32 +0900 (JST) Received: from g01jpexchyt02.g01.fujitsu.local (g01jpexchyt02.g01.fujitsu.local [10.128.194.41]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 6D3FC1DB8052 for ; Wed, 18 Jul 2012 19:51:32 +0900 (JST) Message-ID: <5006951F.4040801@jp.fujitsu.com> Date: Wed, 18 Jul 2012 19:51:11 +0900 From: Yasuaki Ishimatsu MIME-Version: 1.0 Subject: Re: [RFC PATCH v4 4/13] memory-hotplug : remove /sys/firmware/memmap/X sysfs References: <50068974.1070409@jp.fujitsu.com> <50068B54.5070907@jp.fujitsu.com> <500690E0.40204@cn.fujitsu.com> In-Reply-To: <500690E0.40204@cn.fujitsu.com> Content-Type: text/plain; charset="ISO-2022-JP" 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, 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 Hi Wen, 2012/07/18 19:33, Wen Congyang wrote: > At 07/18/2012 06:09 PM, Yasuaki Ishimatsu Wrote: >> When (hot)adding memory into system, /sys/firmware/memmap/X/{end, start, type} >> sysfs files are created. But there is no code to remove these files. The patch >> implements the function to remove them. >> >> Note : The code does not free firmware_map_entry since there is no way to free >> memory which is allocated by bootmem. >> >> 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/firmware/memmap.c | 78 ++++++++++++++++++++++++++++++++++++++++++- >> include/linux/firmware-map.h | 6 +++ >> mm/memory_hotplug.c | 9 +++- >> 3 files changed, 90 insertions(+), 3 deletions(-) >> >> Index: linux-3.5-rc6/mm/memory_hotplug.c >> =================================================================== >> --- linux-3.5-rc6.orig/mm/memory_hotplug.c 2012-07-18 17:20:05.670024283 +0900 >> +++ linux-3.5-rc6/mm/memory_hotplug.c 2012-07-18 17:51:03.933189930 +0900 >> @@ -1012,9 +1012,9 @@ int offline_memory(u64 start, u64 size) >> return offline_pages(start_pfn, end_pfn, 120 * HZ); >> } >> >> -int remove_memory(int nid, u64 start, u64 size) >> +int __ref remove_memory(int nid, u64 start, u64 size) >> { >> - int ret = -EBUSY; >> + int ret = 0; >> lock_memory_hotplug(); >> /* >> * The memory might become online by other task, even if you offine it. >> @@ -1025,8 +1025,13 @@ int remove_memory(int nid, u64 start, u6 >> "because the memmory range is online\n", >> start, start + size); >> ret = -EAGAIN; >> + goto out; >> } >> >> + /* remove memmap entry */ >> + firmware_map_remove(start, start + size, "System RAM"); >> + >> +out: >> unlock_memory_hotplug(); >> return ret; >> >> Index: linux-3.5-rc6/include/linux/firmware-map.h >> =================================================================== >> --- linux-3.5-rc6.orig/include/linux/firmware-map.h 2012-07-18 17:19:37.007382563 +0900 >> +++ linux-3.5-rc6/include/linux/firmware-map.h 2012-07-18 17:42:20.804730245 +0900 >> @@ -25,6 +25,7 @@ >> >> int firmware_map_add_early(u64 start, u64 end, const char *type); >> int firmware_map_add_hotplug(u64 start, u64 end, const char *type); >> +int firmware_map_remove(u64 start, u64 end, const char *type); >> >> #else /* CONFIG_FIRMWARE_MEMMAP */ >> >> @@ -38,6 +39,11 @@ static inline int firmware_map_add_hotpl >> return 0; >> } >> >> +static inline int firmware_map_remove(u64 start, u64 end, const char *type) >> +{ >> + return 0; >> +} >> + >> #endif /* CONFIG_FIRMWARE_MEMMAP */ >> >> #endif /* _LINUX_FIRMWARE_MAP_H */ >> Index: linux-3.5-rc6/drivers/firmware/memmap.c >> =================================================================== >> --- linux-3.5-rc6.orig/drivers/firmware/memmap.c 2012-07-18 17:19:43.618300182 +0900 >> +++ linux-3.5-rc6/drivers/firmware/memmap.c 2012-07-18 17:42:20.846729721 +0900 >> @@ -21,6 +21,7 @@ >> #include >> #include >> #include >> +#include >> >> /* >> * Data types ------------------------------------------------------------------ >> @@ -79,7 +80,22 @@ static const struct sysfs_ops memmap_att >> .show = memmap_attr_show, >> }; >> >> +#define to_memmap_entry(obj) container_of(obj, struct firmware_map_entry, kobj) >> + >> +static void release_firmware_map_entry(struct kobject *kobj) >> +{ >> + struct firmware_map_entry *entry = to_memmap_entry(kobj); >> + struct page *page; >> + >> + page = virt_to_page(entry); >> + if (PageSlab(page) || PageCompound(page)) >> + kfree(entry); > > IIRC, this function's implementation is changed. Why do you do it? > If PageCompound(page), should we check page->first_page's flags? I forgot to write the change to change log. Jiang and Christoph discussed how to find the slab page: - https://lkml.org/lkml/2012/7/6/333 Then, Christoph proposed this method. So I changed it. Thanks, Yasuaki Ishimatsu > > Thanks > Wen Congyang > >> + >> + /* There is no way to free memory allocated from bootmem*/ >> +} >> + >> static struct kobj_type memmap_ktype = { >> + .release = release_firmware_map_entry, >> .sysfs_ops = &memmap_attr_ops, >> .default_attrs = def_attrs, >> }; >> @@ -123,6 +139,16 @@ static int firmware_map_add_entry(u64 st >> return 0; >> } >> >> +/** >> + * firmware_map_remove_entry() - Does the real work to remove a firmware >> + * memmap entry. >> + * @entry: removed entry. >> + **/ >> +static inline void firmware_map_remove_entry(struct firmware_map_entry *entry) >> +{ >> + list_del(&entry->list); >> +} >> + >> /* >> * Add memmap entry on sysfs >> */ >> @@ -144,6 +170,31 @@ static int add_sysfs_fw_map_entry(struct >> return 0; >> } >> >> +/* >> + * Remove memmap entry on sysfs >> + */ >> +static inline void remove_sysfs_fw_map_entry(struct firmware_map_entry *entry) >> +{ >> + kobject_put(&entry->kobj); >> +} >> + >> +/* >> + * Search memmap entry >> + */ >> + >> +struct firmware_map_entry * __meminit >> +find_firmware_map_entry(u64 start, u64 end, const char *type) >> +{ >> + struct firmware_map_entry *entry; >> + >> + list_for_each_entry(entry, &map_entries, list) >> + if ((entry->start == start) && (entry->end == end) && >> + (!strcmp(entry->type, type))) >> + return entry; >> + >> + return NULL; >> +} >> + >> /** >> * firmware_map_add_hotplug() - Adds a firmware mapping entry when we do >> * memory hotplug. >> @@ -196,6 +247,32 @@ int __init firmware_map_add_early(u64 st >> return firmware_map_add_entry(start, end, type, entry); >> } >> >> +/** >> + * firmware_map_remove() - remove a firmware mapping entry >> + * @start: Start of the memory range. >> + * @end: End of the memory range. >> + * @type: Type of the memory range. >> + * >> + * removes a firmware mapping entry. >> + * >> + * Returns 0 on success, or -EINVAL if no entry. >> + **/ >> +int __meminit firmware_map_remove(u64 start, u64 end, const char *type) >> +{ >> + struct firmware_map_entry *entry; >> + >> + entry = find_firmware_map_entry(start, end - 1, type); >> + if (!entry) >> + return -EINVAL; >> + >> + firmware_map_remove_entry(entry); >> + >> + /* remove the memmap entry */ >> + remove_sysfs_fw_map_entry(entry); >> + >> + return 0; >> +} >> + >> /* >> * Sysfs functions ------------------------------------------------------------- >> */ >> @@ -218,7 +295,6 @@ static ssize_t type_show(struct firmware >> } >> >> #define to_memmap_attr(_attr) container_of(_attr, struct memmap_attribute, attr) >> -#define to_memmap_entry(obj) container_of(obj, struct firmware_map_entry, kobj) >> >> static ssize_t memmap_attr_show(struct kobject *kobj, >> struct attribute *attr, char *buf) >> >> -- >> 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 >> > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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