linux-sg2042/include/linux/memory_hotplug.h

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#ifndef __LINUX_MEMORY_HOTPLUG_H
#define __LINUX_MEMORY_HOTPLUG_H
#include <linux/mmzone.h>
#include <linux/spinlock.h>
#include <linux/notifier.h>
#include <linux/bug.h>
struct page;
struct zone;
struct pglist_data;
struct mem_section;
struct memory_block;
#ifdef CONFIG_MEMORY_HOTPLUG
memory hotplug: register section/node id to free This patch set is to free pages which is allocated by bootmem for memory-hotremove. Some structures of memory management are allocated by bootmem. ex) memmap, etc. To remove memory physically, some of them must be freed according to circumstance. This patch set makes basis to free those pages, and free memmaps. Basic my idea is using remain members of struct page to remember information of users of bootmem (section number or node id). When the section is removing, kernel can confirm it. By this information, some issues can be solved. 1) When the memmap of removing section is allocated on other section by bootmem, it should/can be free. 2) When the memmap of removing section is allocated on the same section, it shouldn't be freed. Because the section has to be logical memory offlined already and all pages must be isolated against page allocater. If it is freed, page allocator may use it which will be removed physically soon. 3) When removing section has other section's memmap, kernel will be able to show easily which section should be removed before it for user. (Not implemented yet) 4) When the above case 2), the page isolation will be able to check and skip memmap's page when logical memory offline (offline_pages()). Current page isolation code fails in this case because this page is just reserved page and it can't distinguish this pages can be removed or not. But, it will be able to do by this patch. (Not implemented yet.) 5) The node information like pgdat has similar issues. But, this will be able to be solved too by this. (Not implemented yet, but, remembering node id in the pages.) Fortunately, current bootmem allocator just keeps PageReserved flags, and doesn't use any other members of page struct. The users of bootmem doesn't use them too. This patch: This is to register information which is node or section's id. Kernel can distinguish which node/section uses the pages allcated by bootmem. This is basis for hot-remove sections or nodes. Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 17:13:31 +08:00
/*
* Types for free bootmem stored in page->lru.next. These have to be in
* some random range in unsigned long space for debugging purposes.
memory hotplug: register section/node id to free This patch set is to free pages which is allocated by bootmem for memory-hotremove. Some structures of memory management are allocated by bootmem. ex) memmap, etc. To remove memory physically, some of them must be freed according to circumstance. This patch set makes basis to free those pages, and free memmaps. Basic my idea is using remain members of struct page to remember information of users of bootmem (section number or node id). When the section is removing, kernel can confirm it. By this information, some issues can be solved. 1) When the memmap of removing section is allocated on other section by bootmem, it should/can be free. 2) When the memmap of removing section is allocated on the same section, it shouldn't be freed. Because the section has to be logical memory offlined already and all pages must be isolated against page allocater. If it is freed, page allocator may use it which will be removed physically soon. 3) When removing section has other section's memmap, kernel will be able to show easily which section should be removed before it for user. (Not implemented yet) 4) When the above case 2), the page isolation will be able to check and skip memmap's page when logical memory offline (offline_pages()). Current page isolation code fails in this case because this page is just reserved page and it can't distinguish this pages can be removed or not. But, it will be able to do by this patch. (Not implemented yet.) 5) The node information like pgdat has similar issues. But, this will be able to be solved too by this. (Not implemented yet, but, remembering node id in the pages.) Fortunately, current bootmem allocator just keeps PageReserved flags, and doesn't use any other members of page struct. The users of bootmem doesn't use them too. This patch: This is to register information which is node or section's id. Kernel can distinguish which node/section uses the pages allcated by bootmem. This is basis for hot-remove sections or nodes. Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 17:13:31 +08:00
*/
enum {
MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE = 12,
SECTION_INFO = MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE,
MIX_SECTION_INFO,
NODE_INFO,
MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE = NODE_INFO,
};
memory hotplug: register section/node id to free This patch set is to free pages which is allocated by bootmem for memory-hotremove. Some structures of memory management are allocated by bootmem. ex) memmap, etc. To remove memory physically, some of them must be freed according to circumstance. This patch set makes basis to free those pages, and free memmaps. Basic my idea is using remain members of struct page to remember information of users of bootmem (section number or node id). When the section is removing, kernel can confirm it. By this information, some issues can be solved. 1) When the memmap of removing section is allocated on other section by bootmem, it should/can be free. 2) When the memmap of removing section is allocated on the same section, it shouldn't be freed. Because the section has to be logical memory offlined already and all pages must be isolated against page allocater. If it is freed, page allocator may use it which will be removed physically soon. 3) When removing section has other section's memmap, kernel will be able to show easily which section should be removed before it for user. (Not implemented yet) 4) When the above case 2), the page isolation will be able to check and skip memmap's page when logical memory offline (offline_pages()). Current page isolation code fails in this case because this page is just reserved page and it can't distinguish this pages can be removed or not. But, it will be able to do by this patch. (Not implemented yet.) 5) The node information like pgdat has similar issues. But, this will be able to be solved too by this. (Not implemented yet, but, remembering node id in the pages.) Fortunately, current bootmem allocator just keeps PageReserved flags, and doesn't use any other members of page struct. The users of bootmem doesn't use them too. This patch: This is to register information which is node or section's id. Kernel can distinguish which node/section uses the pages allcated by bootmem. This is basis for hot-remove sections or nodes. Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 17:13:31 +08:00
/* Types for control the zone type of onlined and offlined memory */
mm, memory-hotplug: dynamic configure movable memory and portion memory Add online_movable and online_kernel for logic memory hotplug. This is the dynamic version of "movablecore" & "kernelcore". We have the same reason to introduce it as to introduce "movablecore" & "kernelcore". It has the same motive as "movablecore" & "kernelcore", but it is dynamic/running-time: o We can configure memory as kernelcore or movablecore after boot. Userspace workload is increased, we need more hugepage, we can't use "online_movable" to add memory and allow the system use more THP(transparent-huge-page), vice-verse when kernel workload is increase. Also help for virtualization to dynamic configure host/guest's memory, to save/(reduce waste) memory. Memory capacity on Demand o When a new node is physically online after boot, we need to use "online_movable" or "online_kernel" to configure/portion it as we expected when we logic-online it. This configuration also helps for physically-memory-migrate. o all benefit as the same as existed "movablecore" & "kernelcore". o Preparing for movable-node, which is very important for power-saving, hardware partitioning and high-available-system(hardware fault management). (Note, we don't introduce movable-node here.) Action behavior: When a memoryblock/memorysection is onlined by "online_movable", the kernel will not have directly reference to the page of the memoryblock, thus we can remove that memory any time when needed. When it is online by "online_kernel", the kernel can use it. When it is online by "online", the zone type doesn't changed. Current constraints: Only the memoryblock which is adjacent to the ZONE_MOVABLE can be online from ZONE_NORMAL to ZONE_MOVABLE. [akpm@linux-foundation.org: use min_t, cleanups] Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-12 08:03:16 +08:00
enum {
MMOP_OFFLINE = -1,
MMOP_ONLINE_KEEP,
MMOP_ONLINE_KERNEL,
MMOP_ONLINE_MOVABLE,
mm, memory-hotplug: dynamic configure movable memory and portion memory Add online_movable and online_kernel for logic memory hotplug. This is the dynamic version of "movablecore" & "kernelcore". We have the same reason to introduce it as to introduce "movablecore" & "kernelcore". It has the same motive as "movablecore" & "kernelcore", but it is dynamic/running-time: o We can configure memory as kernelcore or movablecore after boot. Userspace workload is increased, we need more hugepage, we can't use "online_movable" to add memory and allow the system use more THP(transparent-huge-page), vice-verse when kernel workload is increase. Also help for virtualization to dynamic configure host/guest's memory, to save/(reduce waste) memory. Memory capacity on Demand o When a new node is physically online after boot, we need to use "online_movable" or "online_kernel" to configure/portion it as we expected when we logic-online it. This configuration also helps for physically-memory-migrate. o all benefit as the same as existed "movablecore" & "kernelcore". o Preparing for movable-node, which is very important for power-saving, hardware partitioning and high-available-system(hardware fault management). (Note, we don't introduce movable-node here.) Action behavior: When a memoryblock/memorysection is onlined by "online_movable", the kernel will not have directly reference to the page of the memoryblock, thus we can remove that memory any time when needed. When it is online by "online_kernel", the kernel can use it. When it is online by "online", the zone type doesn't changed. Current constraints: Only the memoryblock which is adjacent to the ZONE_MOVABLE can be online from ZONE_NORMAL to ZONE_MOVABLE. [akpm@linux-foundation.org: use min_t, cleanups] Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-12 08:03:16 +08:00
};
/*
* pgdat resizing functions
*/
static inline
void pgdat_resize_lock(struct pglist_data *pgdat, unsigned long *flags)
{
spin_lock_irqsave(&pgdat->node_size_lock, *flags);
}
static inline
void pgdat_resize_unlock(struct pglist_data *pgdat, unsigned long *flags)
{
spin_unlock_irqrestore(&pgdat->node_size_lock, *flags);
}
static inline
void pgdat_resize_init(struct pglist_data *pgdat)
{
spin_lock_init(&pgdat->node_size_lock);
}
/*
* Zone resizing functions
mm, memory-hotplug: dynamic configure movable memory and portion memory Add online_movable and online_kernel for logic memory hotplug. This is the dynamic version of "movablecore" & "kernelcore". We have the same reason to introduce it as to introduce "movablecore" & "kernelcore". It has the same motive as "movablecore" & "kernelcore", but it is dynamic/running-time: o We can configure memory as kernelcore or movablecore after boot. Userspace workload is increased, we need more hugepage, we can't use "online_movable" to add memory and allow the system use more THP(transparent-huge-page), vice-verse when kernel workload is increase. Also help for virtualization to dynamic configure host/guest's memory, to save/(reduce waste) memory. Memory capacity on Demand o When a new node is physically online after boot, we need to use "online_movable" or "online_kernel" to configure/portion it as we expected when we logic-online it. This configuration also helps for physically-memory-migrate. o all benefit as the same as existed "movablecore" & "kernelcore". o Preparing for movable-node, which is very important for power-saving, hardware partitioning and high-available-system(hardware fault management). (Note, we don't introduce movable-node here.) Action behavior: When a memoryblock/memorysection is onlined by "online_movable", the kernel will not have directly reference to the page of the memoryblock, thus we can remove that memory any time when needed. When it is online by "online_kernel", the kernel can use it. When it is online by "online", the zone type doesn't changed. Current constraints: Only the memoryblock which is adjacent to the ZONE_MOVABLE can be online from ZONE_NORMAL to ZONE_MOVABLE. [akpm@linux-foundation.org: use min_t, cleanups] Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-12 08:03:16 +08:00
*
* Note: any attempt to resize a zone should has pgdat_resize_lock()
* zone_span_writelock() both held. This ensure the size of a zone
* can't be changed while pgdat_resize_lock() held.
*/
static inline unsigned zone_span_seqbegin(struct zone *zone)
{
return read_seqbegin(&zone->span_seqlock);
}
static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
{
return read_seqretry(&zone->span_seqlock, iv);
}
static inline void zone_span_writelock(struct zone *zone)
{
write_seqlock(&zone->span_seqlock);
}
static inline void zone_span_writeunlock(struct zone *zone)
{
write_sequnlock(&zone->span_seqlock);
}
static inline void zone_seqlock_init(struct zone *zone)
{
seqlock_init(&zone->span_seqlock);
}
extern int zone_grow_free_lists(struct zone *zone, unsigned long new_nr_pages);
extern int zone_grow_waitqueues(struct zone *zone, unsigned long nr_pages);
extern int add_one_highpage(struct page *page, int pfn, int bad_ppro);
/* VM interface that may be used by firmware interface */
mm, memory-hotplug: dynamic configure movable memory and portion memory Add online_movable and online_kernel for logic memory hotplug. This is the dynamic version of "movablecore" & "kernelcore". We have the same reason to introduce it as to introduce "movablecore" & "kernelcore". It has the same motive as "movablecore" & "kernelcore", but it is dynamic/running-time: o We can configure memory as kernelcore or movablecore after boot. Userspace workload is increased, we need more hugepage, we can't use "online_movable" to add memory and allow the system use more THP(transparent-huge-page), vice-verse when kernel workload is increase. Also help for virtualization to dynamic configure host/guest's memory, to save/(reduce waste) memory. Memory capacity on Demand o When a new node is physically online after boot, we need to use "online_movable" or "online_kernel" to configure/portion it as we expected when we logic-online it. This configuration also helps for physically-memory-migrate. o all benefit as the same as existed "movablecore" & "kernelcore". o Preparing for movable-node, which is very important for power-saving, hardware partitioning and high-available-system(hardware fault management). (Note, we don't introduce movable-node here.) Action behavior: When a memoryblock/memorysection is onlined by "online_movable", the kernel will not have directly reference to the page of the memoryblock, thus we can remove that memory any time when needed. When it is online by "online_kernel", the kernel can use it. When it is online by "online", the zone type doesn't changed. Current constraints: Only the memoryblock which is adjacent to the ZONE_MOVABLE can be online from ZONE_NORMAL to ZONE_MOVABLE. [akpm@linux-foundation.org: use min_t, cleanups] Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-12 08:03:16 +08:00
extern int online_pages(unsigned long, unsigned long, int);
extern int test_pages_in_a_zone(unsigned long, unsigned long);
extern void __offline_isolated_pages(unsigned long, unsigned long);
typedef void (*online_page_callback_t)(struct page *page);
extern int set_online_page_callback(online_page_callback_t callback);
extern int restore_online_page_callback(online_page_callback_t callback);
extern void __online_page_set_limits(struct page *page);
extern void __online_page_increment_counters(struct page *page);
extern void __online_page_free(struct page *page);
extern int try_online_node(int nid);
#ifdef CONFIG_MEMORY_HOTREMOVE
extern bool is_pageblock_removable_nolock(struct page *page);
extern int arch_remove_memory(u64 start, u64 size);
extern int __remove_pages(struct zone *zone, unsigned long start_pfn,
unsigned long nr_pages);
#endif /* CONFIG_MEMORY_HOTREMOVE */
/* reasonably generic interface to expand the physical pages in a zone */
mm: show node to memory section relationship with symlinks in sysfs Show node to memory section relationship with symlinks in sysfs Add /sys/devices/system/node/nodeX/memoryY symlinks for all the memory sections located on nodeX. For example: /sys/devices/system/node/node1/memory135 -> ../../memory/memory135 indicates that memory section 135 resides on node1. Also revises documentation to cover this change as well as updating Documentation/ABI/testing/sysfs-devices-memory to include descriptions of memory hotremove files 'phys_device', 'phys_index', and 'state' that were previously not described there. In addition to it always being a good policy to provide users with the maximum possible amount of physical location information for resources that can be hot-added and/or hot-removed, the following are some (but likely not all) of the user benefits provided by this change. Immediate: - Provides information needed to determine the specific node on which a defective DIMM is located. This will reduce system downtime when the node or defective DIMM is swapped out. - Prevents unintended onlining of a memory section that was previously offlined due to a defective DIMM. This could happen during node hot-add when the user or node hot-add assist script onlines _all_ offlined sections due to user or script inability to identify the specific memory sections located on the hot-added node. The consequences of reintroducing the defective memory could be ugly. - Provides information needed to vary the amount and distribution of memory on specific nodes for testing or debugging purposes. Future: - Will provide information needed to identify the memory sections that need to be offlined prior to physical removal of a specific node. Symlink creation during boot was tested on 2-node x86_64, 2-node ppc64, and 2-node ia64 systems. Symlink creation during physical memory hot-add tested on a 2-node x86_64 system. Signed-off-by: Gary Hade <garyhade@us.ibm.com> Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-07 06:39:14 +08:00
extern int __add_pages(int nid, struct zone *zone, unsigned long start_pfn,
unsigned long nr_pages);
#ifdef CONFIG_NUMA
extern int memory_add_physaddr_to_nid(u64 start);
#else
static inline int memory_add_physaddr_to_nid(u64 start)
{
return 0;
}
#endif
#ifdef CONFIG_HAVE_ARCH_NODEDATA_EXTENSION
/*
* For supporting node-hotadd, we have to allocate a new pgdat.
*
* If an arch has generic style NODE_DATA(),
* node_data[nid] = kzalloc() works well. But it depends on the architecture.
*
* In general, generic_alloc_nodedata() is used.
* Now, arch_free_nodedata() is just defined for error path of node_hot_add.
*
*/
extern pg_data_t *arch_alloc_nodedata(int nid);
extern void arch_free_nodedata(pg_data_t *pgdat);
extern void arch_refresh_nodedata(int nid, pg_data_t *pgdat);
#else /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */
#define arch_alloc_nodedata(nid) generic_alloc_nodedata(nid)
#define arch_free_nodedata(pgdat) generic_free_nodedata(pgdat)
#ifdef CONFIG_NUMA
/*
* If ARCH_HAS_NODEDATA_EXTENSION=n, this func is used to allocate pgdat.
* XXX: kmalloc_node() can't work well to get new node's memory at this time.
* Because, pgdat for the new node is not allocated/initialized yet itself.
* To use new node's memory, more consideration will be necessary.
*/
#define generic_alloc_nodedata(nid) \
({ \
kzalloc(sizeof(pg_data_t), GFP_KERNEL); \
})
/*
* This definition is just for error path in node hotadd.
* For node hotremove, we have to replace this.
*/
#define generic_free_nodedata(pgdat) kfree(pgdat)
extern pg_data_t *node_data[];
static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat)
{
node_data[nid] = pgdat;
}
#else /* !CONFIG_NUMA */
/* never called */
static inline pg_data_t *generic_alloc_nodedata(int nid)
{
BUG();
return NULL;
}
static inline void generic_free_nodedata(pg_data_t *pgdat)
{
}
static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat)
{
}
#endif /* CONFIG_NUMA */
#endif /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */
memory-hotplug: implement register_page_bootmem_info_section of sparse-vmemmap For removing memmap region of sparse-vmemmap which is allocated bootmem, memmap region of sparse-vmemmap needs to be registered by get_page_bootmem(). So the patch searches pages of virtual mapping and registers the pages by get_page_bootmem(). NOTE: register_page_bootmem_memmap() is not implemented for ia64, ppc, s390, and sparc. So introduce CONFIG_HAVE_BOOTMEM_INFO_NODE and revert register_page_bootmem_info_node() when platform doesn't support it. It's implemented by adding a new Kconfig option named CONFIG_HAVE_BOOTMEM_INFO_NODE, which will be automatically selected by memory-hotplug feature fully supported archs(currently only on x86_64). Since we have 2 config options called MEMORY_HOTPLUG and MEMORY_HOTREMOVE used for memory hot-add and hot-remove separately, and codes in function register_page_bootmem_info_node() are only used for collecting infomation for hot-remove, so reside it under MEMORY_HOTREMOVE. Besides page_isolation.c selected by MEMORY_ISOLATION under MEMORY_HOTPLUG is also such case, move it too. [mhocko@suse.cz: put register_page_bootmem_memmap inside CONFIG_MEMORY_HOTPLUG_SPARSE] [linfeng@cn.fujitsu.com: introduce CONFIG_HAVE_BOOTMEM_INFO_NODE and revert register_page_bootmem_info_node()] [mhocko@suse.cz: remove the arch specific functions without any implementation] [linfeng@cn.fujitsu.com: mm/Kconfig: move auto selects from MEMORY_HOTPLUG to MEMORY_HOTREMOVE as needed] [rientjes@google.com: fix defined but not used warning] Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Reviewed-by: Wu Jianguo <wujianguo@huawei.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Lin Feng <linfeng@cn.fujitsu.com> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-23 08:33:00 +08:00
#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
extern void register_page_bootmem_info_node(struct pglist_data *pgdat);
#else
memory hotplug: register section/node id to free This patch set is to free pages which is allocated by bootmem for memory-hotremove. Some structures of memory management are allocated by bootmem. ex) memmap, etc. To remove memory physically, some of them must be freed according to circumstance. This patch set makes basis to free those pages, and free memmaps. Basic my idea is using remain members of struct page to remember information of users of bootmem (section number or node id). When the section is removing, kernel can confirm it. By this information, some issues can be solved. 1) When the memmap of removing section is allocated on other section by bootmem, it should/can be free. 2) When the memmap of removing section is allocated on the same section, it shouldn't be freed. Because the section has to be logical memory offlined already and all pages must be isolated against page allocater. If it is freed, page allocator may use it which will be removed physically soon. 3) When removing section has other section's memmap, kernel will be able to show easily which section should be removed before it for user. (Not implemented yet) 4) When the above case 2), the page isolation will be able to check and skip memmap's page when logical memory offline (offline_pages()). Current page isolation code fails in this case because this page is just reserved page and it can't distinguish this pages can be removed or not. But, it will be able to do by this patch. (Not implemented yet.) 5) The node information like pgdat has similar issues. But, this will be able to be solved too by this. (Not implemented yet, but, remembering node id in the pages.) Fortunately, current bootmem allocator just keeps PageReserved flags, and doesn't use any other members of page struct. The users of bootmem doesn't use them too. This patch: This is to register information which is node or section's id. Kernel can distinguish which node/section uses the pages allcated by bootmem. This is basis for hot-remove sections or nodes. Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 17:13:31 +08:00
static inline void register_page_bootmem_info_node(struct pglist_data *pgdat)
{
}
#endif
memory-hotplug: implement register_page_bootmem_info_section of sparse-vmemmap For removing memmap region of sparse-vmemmap which is allocated bootmem, memmap region of sparse-vmemmap needs to be registered by get_page_bootmem(). So the patch searches pages of virtual mapping and registers the pages by get_page_bootmem(). NOTE: register_page_bootmem_memmap() is not implemented for ia64, ppc, s390, and sparc. So introduce CONFIG_HAVE_BOOTMEM_INFO_NODE and revert register_page_bootmem_info_node() when platform doesn't support it. It's implemented by adding a new Kconfig option named CONFIG_HAVE_BOOTMEM_INFO_NODE, which will be automatically selected by memory-hotplug feature fully supported archs(currently only on x86_64). Since we have 2 config options called MEMORY_HOTPLUG and MEMORY_HOTREMOVE used for memory hot-add and hot-remove separately, and codes in function register_page_bootmem_info_node() are only used for collecting infomation for hot-remove, so reside it under MEMORY_HOTREMOVE. Besides page_isolation.c selected by MEMORY_ISOLATION under MEMORY_HOTPLUG is also such case, move it too. [mhocko@suse.cz: put register_page_bootmem_memmap inside CONFIG_MEMORY_HOTPLUG_SPARSE] [linfeng@cn.fujitsu.com: introduce CONFIG_HAVE_BOOTMEM_INFO_NODE and revert register_page_bootmem_info_node()] [mhocko@suse.cz: remove the arch specific functions without any implementation] [linfeng@cn.fujitsu.com: mm/Kconfig: move auto selects from MEMORY_HOTPLUG to MEMORY_HOTREMOVE as needed] [rientjes@google.com: fix defined but not used warning] Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Reviewed-by: Wu Jianguo <wujianguo@huawei.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Lin Feng <linfeng@cn.fujitsu.com> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-23 08:33:00 +08:00
extern void put_page_bootmem(struct page *page);
extern void get_page_bootmem(unsigned long ingo, struct page *page,
unsigned long type);
memory hotplug: register section/node id to free This patch set is to free pages which is allocated by bootmem for memory-hotremove. Some structures of memory management are allocated by bootmem. ex) memmap, etc. To remove memory physically, some of them must be freed according to circumstance. This patch set makes basis to free those pages, and free memmaps. Basic my idea is using remain members of struct page to remember information of users of bootmem (section number or node id). When the section is removing, kernel can confirm it. By this information, some issues can be solved. 1) When the memmap of removing section is allocated on other section by bootmem, it should/can be free. 2) When the memmap of removing section is allocated on the same section, it shouldn't be freed. Because the section has to be logical memory offlined already and all pages must be isolated against page allocater. If it is freed, page allocator may use it which will be removed physically soon. 3) When removing section has other section's memmap, kernel will be able to show easily which section should be removed before it for user. (Not implemented yet) 4) When the above case 2), the page isolation will be able to check and skip memmap's page when logical memory offline (offline_pages()). Current page isolation code fails in this case because this page is just reserved page and it can't distinguish this pages can be removed or not. But, it will be able to do by this patch. (Not implemented yet.) 5) The node information like pgdat has similar issues. But, this will be able to be solved too by this. (Not implemented yet, but, remembering node id in the pages.) Fortunately, current bootmem allocator just keeps PageReserved flags, and doesn't use any other members of page struct. The users of bootmem doesn't use them too. This patch: This is to register information which is node or section's id. Kernel can distinguish which node/section uses the pages allcated by bootmem. This is basis for hot-remove sections or nodes. Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 17:13:31 +08:00
mem-hotplug: implement get/put_online_mems kmem_cache_{create,destroy,shrink} need to get a stable value of cpu/node online mask, because they init/destroy/access per-cpu/node kmem_cache parts, which can be allocated or destroyed on cpu/mem hotplug. To protect against cpu hotplug, these functions use {get,put}_online_cpus. However, they do nothing to synchronize with memory hotplug - taking the slab_mutex does not eliminate the possibility of race as described in patch 2. What we need there is something like get_online_cpus, but for memory. We already have lock_memory_hotplug, which serves for the purpose, but it's a bit of a hammer right now, because it's backed by a mutex. As a result, it imposes some limitations to locking order, which are not desirable, and can't be used just like get_online_cpus. That's why in patch 1 I substitute it with get/put_online_mems, which work exactly like get/put_online_cpus except they block not cpu, but memory hotplug. [ v1 can be found at https://lkml.org/lkml/2014/4/6/68. I NAK'ed it by myself, because it used an rw semaphore for get/put_online_mems, making them dead lock prune. ] This patch (of 2): {un}lock_memory_hotplug, which is used to synchronize against memory hotplug, is currently backed by a mutex, which makes it a bit of a hammer - threads that only want to get a stable value of online nodes mask won't be able to proceed concurrently. Also, it imposes some strong locking ordering rules on it, which narrows down the set of its usage scenarios. This patch introduces get/put_online_mems, which are the same as get/put_online_cpus, but for memory hotplug, i.e. executing a code inside a get/put_online_mems section will guarantee a stable value of online nodes, present pages, etc. lock_memory_hotplug()/unlock_memory_hotplug() are removed altogether. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-05 07:07:18 +08:00
void get_online_mems(void);
void put_online_mems(void);
mm, hotplug: fix concurrent memory hot-add deadlock There's a deadlock when concurrently hot-adding memory through the probe interface and switching a memory block from offline to online. When hot-adding memory via the probe interface, add_memory() first takes mem_hotplug_begin() and then device_lock() is later taken when registering the newly initialized memory block. This creates a lock dependency of (1) mem_hotplug.lock (2) dev->mutex. When switching a memory block from offline to online, dev->mutex is first grabbed in device_online() when the write(2) transitions an existing memory block from offline to online, and then online_pages() will take mem_hotplug_begin(). This creates a lock inversion between mem_hotplug.lock and dev->mutex. Vitaly reports that this deadlock can happen when kworker handling a probe event races with systemd-udevd switching a memory block's state. This patch requires the state transition to take mem_hotplug_begin() before dev->mutex. Hot-adding memory via the probe interface creates a memory block while holding mem_hotplug_begin(), there is no way to take dev->mutex first in this case. online_pages() and offline_pages() are only called when transitioning memory block state. We now require that mem_hotplug_begin() is taken before calling them -- this requires exporting the mem_hotplug_begin() and mem_hotplug_done() to generic code. In all hot-add and hot-remove cases, mem_hotplug_begin() is done prior to device_online(). This is all that is needed to avoid the deadlock. Signed-off-by: David Rientjes <rientjes@google.com> Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zhang Zhen <zhenzhang.zhang@huawei.com> Cc: Vladimir Davydov <vdavydov@parallels.com> Cc: Wang Nan <wangnan0@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 06:45:11 +08:00
void mem_hotplug_begin(void);
void mem_hotplug_done(void);
#else /* ! CONFIG_MEMORY_HOTPLUG */
/*
* Stub functions for when hotplug is off
*/
static inline void pgdat_resize_lock(struct pglist_data *p, unsigned long *f) {}
static inline void pgdat_resize_unlock(struct pglist_data *p, unsigned long *f) {}
static inline void pgdat_resize_init(struct pglist_data *pgdat) {}
static inline unsigned zone_span_seqbegin(struct zone *zone)
{
return 0;
}
static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
{
return 0;
}
static inline void zone_span_writelock(struct zone *zone) {}
static inline void zone_span_writeunlock(struct zone *zone) {}
static inline void zone_seqlock_init(struct zone *zone) {}
static inline int mhp_notimplemented(const char *func)
{
printk(KERN_WARNING "%s() called, with CONFIG_MEMORY_HOTPLUG disabled\n", func);
dump_stack();
return -ENOSYS;
}
memory hotplug: register section/node id to free This patch set is to free pages which is allocated by bootmem for memory-hotremove. Some structures of memory management are allocated by bootmem. ex) memmap, etc. To remove memory physically, some of them must be freed according to circumstance. This patch set makes basis to free those pages, and free memmaps. Basic my idea is using remain members of struct page to remember information of users of bootmem (section number or node id). When the section is removing, kernel can confirm it. By this information, some issues can be solved. 1) When the memmap of removing section is allocated on other section by bootmem, it should/can be free. 2) When the memmap of removing section is allocated on the same section, it shouldn't be freed. Because the section has to be logical memory offlined already and all pages must be isolated against page allocater. If it is freed, page allocator may use it which will be removed physically soon. 3) When removing section has other section's memmap, kernel will be able to show easily which section should be removed before it for user. (Not implemented yet) 4) When the above case 2), the page isolation will be able to check and skip memmap's page when logical memory offline (offline_pages()). Current page isolation code fails in this case because this page is just reserved page and it can't distinguish this pages can be removed or not. But, it will be able to do by this patch. (Not implemented yet.) 5) The node information like pgdat has similar issues. But, this will be able to be solved too by this. (Not implemented yet, but, remembering node id in the pages.) Fortunately, current bootmem allocator just keeps PageReserved flags, and doesn't use any other members of page struct. The users of bootmem doesn't use them too. This patch: This is to register information which is node or section's id. Kernel can distinguish which node/section uses the pages allcated by bootmem. This is basis for hot-remove sections or nodes. Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 17:13:31 +08:00
static inline void register_page_bootmem_info_node(struct pglist_data *pgdat)
{
}
static inline int try_online_node(int nid)
{
return 0;
}
mem-hotplug: implement get/put_online_mems kmem_cache_{create,destroy,shrink} need to get a stable value of cpu/node online mask, because they init/destroy/access per-cpu/node kmem_cache parts, which can be allocated or destroyed on cpu/mem hotplug. To protect against cpu hotplug, these functions use {get,put}_online_cpus. However, they do nothing to synchronize with memory hotplug - taking the slab_mutex does not eliminate the possibility of race as described in patch 2. What we need there is something like get_online_cpus, but for memory. We already have lock_memory_hotplug, which serves for the purpose, but it's a bit of a hammer right now, because it's backed by a mutex. As a result, it imposes some limitations to locking order, which are not desirable, and can't be used just like get_online_cpus. That's why in patch 1 I substitute it with get/put_online_mems, which work exactly like get/put_online_cpus except they block not cpu, but memory hotplug. [ v1 can be found at https://lkml.org/lkml/2014/4/6/68. I NAK'ed it by myself, because it used an rw semaphore for get/put_online_mems, making them dead lock prune. ] This patch (of 2): {un}lock_memory_hotplug, which is used to synchronize against memory hotplug, is currently backed by a mutex, which makes it a bit of a hammer - threads that only want to get a stable value of online nodes mask won't be able to proceed concurrently. Also, it imposes some strong locking ordering rules on it, which narrows down the set of its usage scenarios. This patch introduces get/put_online_mems, which are the same as get/put_online_cpus, but for memory hotplug, i.e. executing a code inside a get/put_online_mems section will guarantee a stable value of online nodes, present pages, etc. lock_memory_hotplug()/unlock_memory_hotplug() are removed altogether. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Toshi Kani <toshi.kani@hp.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Wen Congyang <wency@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-05 07:07:18 +08:00
static inline void get_online_mems(void) {}
static inline void put_online_mems(void) {}
mm, hotplug: fix concurrent memory hot-add deadlock There's a deadlock when concurrently hot-adding memory through the probe interface and switching a memory block from offline to online. When hot-adding memory via the probe interface, add_memory() first takes mem_hotplug_begin() and then device_lock() is later taken when registering the newly initialized memory block. This creates a lock dependency of (1) mem_hotplug.lock (2) dev->mutex. When switching a memory block from offline to online, dev->mutex is first grabbed in device_online() when the write(2) transitions an existing memory block from offline to online, and then online_pages() will take mem_hotplug_begin(). This creates a lock inversion between mem_hotplug.lock and dev->mutex. Vitaly reports that this deadlock can happen when kworker handling a probe event races with systemd-udevd switching a memory block's state. This patch requires the state transition to take mem_hotplug_begin() before dev->mutex. Hot-adding memory via the probe interface creates a memory block while holding mem_hotplug_begin(), there is no way to take dev->mutex first in this case. online_pages() and offline_pages() are only called when transitioning memory block state. We now require that mem_hotplug_begin() is taken before calling them -- this requires exporting the mem_hotplug_begin() and mem_hotplug_done() to generic code. In all hot-add and hot-remove cases, mem_hotplug_begin() is done prior to device_online(). This is all that is needed to avoid the deadlock. Signed-off-by: David Rientjes <rientjes@google.com> Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com> Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zhang Zhen <zhenzhang.zhang@huawei.com> Cc: Vladimir Davydov <vdavydov@parallels.com> Cc: Wang Nan <wangnan0@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 06:45:11 +08:00
static inline void mem_hotplug_begin(void) {}
static inline void mem_hotplug_done(void) {}
#endif /* ! CONFIG_MEMORY_HOTPLUG */
memory-hotplug: add sysfs removable attribute for hotplug memory remove Memory may be hot-removed on a per-memory-block basis, particularly on POWER where the SPARSEMEM section size often matches the memory-block size. A user-level agent must be able to identify which sections of memory are likely to be removable before attempting the potentially expensive operation. This patch adds a file called "removable" to the memory directory in sysfs to help such an agent. In this patch, a memory block is considered removable if; o It contains only MOVABLE pageblocks o It contains only pageblocks with free pages regardless of pageblock type On the other hand, a memory block starting with a PageReserved() page will never be considered removable. Without this patch, the user-agent is forced to choose a memory block to remove randomly. Sample output of the sysfs files: ./memory/memory0/removable: 0 ./memory/memory1/removable: 0 ./memory/memory2/removable: 0 ./memory/memory3/removable: 0 ./memory/memory4/removable: 0 ./memory/memory5/removable: 0 ./memory/memory6/removable: 0 ./memory/memory7/removable: 1 ./memory/memory8/removable: 0 ./memory/memory9/removable: 0 ./memory/memory10/removable: 0 ./memory/memory11/removable: 0 ./memory/memory12/removable: 0 ./memory/memory13/removable: 0 ./memory/memory14/removable: 0 ./memory/memory15/removable: 0 ./memory/memory16/removable: 0 ./memory/memory17/removable: 1 ./memory/memory18/removable: 1 ./memory/memory19/removable: 1 ./memory/memory20/removable: 1 ./memory/memory21/removable: 1 ./memory/memory22/removable: 1 Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 12:28:19 +08:00
#ifdef CONFIG_MEMORY_HOTREMOVE
extern int is_mem_section_removable(unsigned long pfn, unsigned long nr_pages);
extern void try_offline_node(int nid);
extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages);
extern void remove_memory(int nid, u64 start, u64 size);
memory-hotplug: add sysfs removable attribute for hotplug memory remove Memory may be hot-removed on a per-memory-block basis, particularly on POWER where the SPARSEMEM section size often matches the memory-block size. A user-level agent must be able to identify which sections of memory are likely to be removable before attempting the potentially expensive operation. This patch adds a file called "removable" to the memory directory in sysfs to help such an agent. In this patch, a memory block is considered removable if; o It contains only MOVABLE pageblocks o It contains only pageblocks with free pages regardless of pageblock type On the other hand, a memory block starting with a PageReserved() page will never be considered removable. Without this patch, the user-agent is forced to choose a memory block to remove randomly. Sample output of the sysfs files: ./memory/memory0/removable: 0 ./memory/memory1/removable: 0 ./memory/memory2/removable: 0 ./memory/memory3/removable: 0 ./memory/memory4/removable: 0 ./memory/memory5/removable: 0 ./memory/memory6/removable: 0 ./memory/memory7/removable: 1 ./memory/memory8/removable: 0 ./memory/memory9/removable: 0 ./memory/memory10/removable: 0 ./memory/memory11/removable: 0 ./memory/memory12/removable: 0 ./memory/memory13/removable: 0 ./memory/memory14/removable: 0 ./memory/memory15/removable: 0 ./memory/memory16/removable: 0 ./memory/memory17/removable: 1 ./memory/memory18/removable: 1 ./memory/memory19/removable: 1 ./memory/memory20/removable: 1 ./memory/memory21/removable: 1 ./memory/memory22/removable: 1 Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 12:28:19 +08:00
#else
static inline int is_mem_section_removable(unsigned long pfn,
unsigned long nr_pages)
{
return 0;
}
static inline void try_offline_node(int nid) {}
static inline int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
{
return -EINVAL;
}
static inline void remove_memory(int nid, u64 start, u64 size) {}
memory-hotplug: add sysfs removable attribute for hotplug memory remove Memory may be hot-removed on a per-memory-block basis, particularly on POWER where the SPARSEMEM section size often matches the memory-block size. A user-level agent must be able to identify which sections of memory are likely to be removable before attempting the potentially expensive operation. This patch adds a file called "removable" to the memory directory in sysfs to help such an agent. In this patch, a memory block is considered removable if; o It contains only MOVABLE pageblocks o It contains only pageblocks with free pages regardless of pageblock type On the other hand, a memory block starting with a PageReserved() page will never be considered removable. Without this patch, the user-agent is forced to choose a memory block to remove randomly. Sample output of the sysfs files: ./memory/memory0/removable: 0 ./memory/memory1/removable: 0 ./memory/memory2/removable: 0 ./memory/memory3/removable: 0 ./memory/memory4/removable: 0 ./memory/memory5/removable: 0 ./memory/memory6/removable: 0 ./memory/memory7/removable: 1 ./memory/memory8/removable: 0 ./memory/memory9/removable: 0 ./memory/memory10/removable: 0 ./memory/memory11/removable: 0 ./memory/memory12/removable: 0 ./memory/memory13/removable: 0 ./memory/memory14/removable: 0 ./memory/memory15/removable: 0 ./memory/memory16/removable: 0 ./memory/memory17/removable: 1 ./memory/memory18/removable: 1 ./memory/memory19/removable: 1 ./memory/memory20/removable: 1 ./memory/memory21/removable: 1 ./memory/memory22/removable: 1 Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 12:28:19 +08:00
#endif /* CONFIG_MEMORY_HOTREMOVE */
extern int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,
void *arg, int (*func)(struct memory_block *, void *));
extern int add_memory(int nid, u64 start, u64 size);
memory-hotplug: add zone_for_memory() for selecting zone for new memory This series of patches fixes a problem when adding memory in bad manner. For example: for a x86_64 machine booted with "mem=400M" and with 2GiB memory installed, following commands cause problem: # echo 0x40000000 > /sys/devices/system/memory/probe [ 28.613895] init_memory_mapping: [mem 0x40000000-0x47ffffff] # echo 0x48000000 > /sys/devices/system/memory/probe [ 28.693675] init_memory_mapping: [mem 0x48000000-0x4fffffff] # echo online_movable > /sys/devices/system/memory/memory9/state # echo 0x50000000 > /sys/devices/system/memory/probe [ 29.084090] init_memory_mapping: [mem 0x50000000-0x57ffffff] # echo 0x58000000 > /sys/devices/system/memory/probe [ 29.151880] init_memory_mapping: [mem 0x58000000-0x5fffffff] # echo online_movable > /sys/devices/system/memory/memory11/state # echo online> /sys/devices/system/memory/memory8/state # echo online> /sys/devices/system/memory/memory10/state # echo offline> /sys/devices/system/memory/memory9/state [ 30.558819] Offlined Pages 32768 # free total used free shared buffers cached Mem: 780588 18014398509432020 830552 0 0 51180 -/+ buffers/cache: 18014398509380840 881732 Swap: 0 0 0 This is because the above commands probe higher memory after online a section with online_movable, which causes ZONE_HIGHMEM (or ZONE_NORMAL for systems without ZONE_HIGHMEM) overlaps ZONE_MOVABLE. After the second online_movable, the problem can be observed from zoneinfo: # cat /proc/zoneinfo ... Node 0, zone Movable pages free 65491 min 250 low 312 high 375 scanned 0 spanned 18446744073709518848 present 65536 managed 65536 ... This series of patches solve the problem by checking ZONE_MOVABLE when choosing zone for new memory. If new memory is inside or higher than ZONE_MOVABLE, makes it go there instead. After applying this series of patches, following are free and zoneinfo result (after offlining memory9): bash-4.2# free total used free shared buffers cached Mem: 780956 80112 700844 0 0 51180 -/+ buffers/cache: 28932 752024 Swap: 0 0 0 bash-4.2# cat /proc/zoneinfo Node 0, zone DMA pages free 3389 min 14 low 17 high 21 scanned 0 spanned 4095 present 3998 managed 3977 nr_free_pages 3389 ... start_pfn: 1 inactive_ratio: 1 Node 0, zone DMA32 pages free 73724 min 341 low 426 high 511 scanned 0 spanned 98304 present 98304 managed 92958 nr_free_pages 73724 ... start_pfn: 4096 inactive_ratio: 1 Node 0, zone Normal pages free 32630 min 120 low 150 high 180 scanned 0 spanned 32768 present 32768 managed 32768 nr_free_pages 32630 ... start_pfn: 262144 inactive_ratio: 1 Node 0, zone Movable pages free 65476 min 241 low 301 high 361 scanned 0 spanned 98304 present 65536 managed 65536 nr_free_pages 65476 ... start_pfn: 294912 inactive_ratio: 1 This patch (of 7): Introduce zone_for_memory() in arch independent code for arch_add_memory() use. Many arch_add_memory() function simply selects ZONE_HIGHMEM or ZONE_NORMAL and add new memory into it. However, with the existance of ZONE_MOVABLE, the selection method should be carefully considered: if new, higher memory is added after ZONE_MOVABLE is setup, the default zone and ZONE_MOVABLE may overlap each other. should_add_memory_movable() checks the status of ZONE_MOVABLE. If it has already contain memory, compare the address of new memory and movable memory. If new memory is higher than movable, it should be added into ZONE_MOVABLE instead of default zone. Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: "Mel Gorman" <mgorman@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-07 07:07:36 +08:00
extern int zone_for_memory(int nid, u64 start, u64 size, int zone_default);
extern int arch_add_memory(int nid, u64 start, u64 size);
extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages);
memory-hotplug: check whether all memory blocks are offlined or not when removing memory We remove the memory like this: 1. lock memory hotplug 2. offline a memory block 3. unlock memory hotplug 4. repeat 1-3 to offline all memory blocks 5. lock memory hotplug 6. remove memory(TODO) 7. unlock memory hotplug All memory blocks must be offlined before removing memory. But we don't hold the lock in the whole operation. So we should check whether all memory blocks are offlined before step6. Otherwise, kernel maybe panicked. Offlining a memory block and removing a memory device can be two different operations. Users can just offline some memory blocks without removing the memory device. For this purpose, the kernel has held lock_memory_hotplug() in __offline_pages(). To reuse the code for memory hot-remove, we repeat step 1-3 to offline all the memory blocks, repeatedly lock and unlock memory hotplug, but not hold the memory hotplug lock in the whole operation. Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Wu Jianguo <wujianguo@huawei.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-23 08:32:52 +08:00
extern bool is_memblock_offlined(struct memory_block *mem);
extern void remove_memory(int nid, u64 start, u64 size);
extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn);
extern void sparse_remove_one_section(struct zone *zone, struct mem_section *ms);
memory hotplug: register section/node id to free This patch set is to free pages which is allocated by bootmem for memory-hotremove. Some structures of memory management are allocated by bootmem. ex) memmap, etc. To remove memory physically, some of them must be freed according to circumstance. This patch set makes basis to free those pages, and free memmaps. Basic my idea is using remain members of struct page to remember information of users of bootmem (section number or node id). When the section is removing, kernel can confirm it. By this information, some issues can be solved. 1) When the memmap of removing section is allocated on other section by bootmem, it should/can be free. 2) When the memmap of removing section is allocated on the same section, it shouldn't be freed. Because the section has to be logical memory offlined already and all pages must be isolated against page allocater. If it is freed, page allocator may use it which will be removed physically soon. 3) When removing section has other section's memmap, kernel will be able to show easily which section should be removed before it for user. (Not implemented yet) 4) When the above case 2), the page isolation will be able to check and skip memmap's page when logical memory offline (offline_pages()). Current page isolation code fails in this case because this page is just reserved page and it can't distinguish this pages can be removed or not. But, it will be able to do by this patch. (Not implemented yet.) 5) The node information like pgdat has similar issues. But, this will be able to be solved too by this. (Not implemented yet, but, remembering node id in the pages.) Fortunately, current bootmem allocator just keeps PageReserved flags, and doesn't use any other members of page struct. The users of bootmem doesn't use them too. This patch: This is to register information which is node or section's id. Kernel can distinguish which node/section uses the pages allcated by bootmem. This is basis for hot-remove sections or nodes. Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 17:13:31 +08:00
extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map,
unsigned long pnum);
#endif /* __LINUX_MEMORY_HOTPLUG_H */