From 511c2aba8f07fc45bdcba548cb63f7b8a450c6dc Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Tue, 11 Dec 2012 16:03:16 -0800 Subject: 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 Signed-off-by: Wen Congyang Cc: Yasuaki Ishimatsu Cc: Lai Jiangshan Cc: Jiang Liu Cc: KOSAKI Motohiro Cc: Minchan Kim Cc: Mel Gorman Cc: David Rientjes Cc: Yinghai Lu Cc: Rusty Russell Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memory_hotplug.h | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 95573ec4ee6..4a45c4e5002 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -26,6 +26,13 @@ enum { MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE = NODE_INFO, }; +/* Types for control the zone type of onlined memory */ +enum { + ONLINE_KEEP, + ONLINE_KERNEL, + ONLINE_MOVABLE, +}; + /* * pgdat resizing functions */ @@ -46,6 +53,10 @@ void pgdat_resize_init(struct pglist_data *pgdat) } /* * Zone resizing functions + * + * 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) { @@ -71,7 +82,7 @@ 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 */ -extern int online_pages(unsigned long, unsigned long); +extern int online_pages(unsigned long, unsigned long, int); extern void __offline_isolated_pages(unsigned long, unsigned long); typedef void (*online_page_callback_t)(struct page *page); -- cgit v1.2.3