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authorDavid Hildenbrand <david@redhat.com>2021-09-08 05:55:26 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-09-08 21:50:23 +0300
commit028fc57a1c361116e3bcebfeba4ca87878baaf4f (patch)
tree65f2e2e44292b89807668774829b5758d13d4a76 /include
parente83a437faa625efb2e70924fd3c32ba95610c502 (diff)
downloadlinux-028fc57a1c361116e3bcebfeba4ca87878baaf4f.tar.xz
drivers/base/memory: introduce "memory groups" to logically group memory blocks
In our "auto-movable" memory onlining policy, we want to make decisions across memory blocks of a single memory device. Examples of memory devices include ACPI memory devices (in the simplest case a single DIMM) and virtio-mem. For now, we don't have a connection between a single memory block device and the real memory device. Each memory device consists of 1..X memory block devices. Let's logically group memory blocks belonging to the same memory device in "memory groups". Memory groups can span multiple physical ranges and a memory group itself does not contain any information regarding physical ranges, only properties (e.g., "max_pages") necessary for improved memory onlining. Introduce two memory group types: 1) Static memory group: E.g., a single ACPI memory device, consisting of 1..X memory resources. A memory group consists of 1..Y memory blocks. The whole group is added/removed in one go. If any part cannot get offlined, the whole group cannot be removed. 2) Dynamic memory group: E.g., a single virtio-mem device. Memory is dynamically added/removed in a fixed granularity, called a "unit", consisting of 1..X memory blocks. A unit is added/removed in one go. If any part of a unit cannot get offlined, the whole unit cannot be removed. In case of 1) we usually want either all memory managed by ZONE_MOVABLE or none. In case of 2) we usually want to have as many units as possible managed by ZONE_MOVABLE. We want a single unit to be of the same type. For now, memory groups are an internal concept that is not exposed to user space; we might want to change that in the future, though. add_memory() users can specify a mgid instead of a nid when passing the MHP_NID_IS_MGID flag. Link: https://lkml.kernel.org/r/20210806124715.17090-4-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hui Zhu <teawater@gmail.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Len Brown <lenb@kernel.org> Cc: Marek Kedzierski <mkedzier@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/memory.h46
-rw-r--r--include/linux/memory_hotplug.h5
2 files changed, 50 insertions, 1 deletions
diff --git a/include/linux/memory.h b/include/linux/memory.h
index 97e92e8b556a..d505c12c5c77 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -23,6 +23,42 @@
#define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS)
+/**
+ * struct memory_group - a logical group of memory blocks
+ * @nid: The node id for all memory blocks inside the memory group.
+ * @blocks: List of all memory blocks belonging to this memory group.
+ * @is_dynamic: The memory group type: static vs. dynamic
+ * @s.max_pages: Valid with &memory_group.is_dynamic == false. The maximum
+ * number of pages we'll have in this static memory group.
+ * @d.unit_pages: Valid with &memory_group.is_dynamic == true. Unit in pages
+ * in which memory is added/removed in this dynamic memory group.
+ * This granularity defines the alignment of a unit in physical
+ * address space; it has to be at least as big as a single
+ * memory block.
+ *
+ * A memory group logically groups memory blocks; each memory block
+ * belongs to at most one memory group. A memory group corresponds to
+ * a memory device, such as a DIMM or a NUMA node, which spans multiple
+ * memory blocks and might even span multiple non-contiguous physical memory
+ * ranges.
+ *
+ * Modification of members after registration is serialized by memory
+ * hot(un)plug code.
+ */
+struct memory_group {
+ int nid;
+ struct list_head memory_blocks;
+ bool is_dynamic;
+ union {
+ struct {
+ unsigned long max_pages;
+ } s;
+ struct {
+ unsigned long unit_pages;
+ } d;
+ };
+};
+
struct memory_block {
unsigned long start_section_nr;
unsigned long state; /* serialized by the dev->lock */
@@ -34,6 +70,8 @@ struct memory_block {
* lay at the beginning of the memory block.
*/
unsigned long nr_vmemmap_pages;
+ struct memory_group *group; /* group (if any) for this block */
+ struct list_head group_next; /* next block inside memory group */
};
int arch_get_memory_phys_device(unsigned long start_pfn);
@@ -86,7 +124,8 @@ static inline int memory_notify(unsigned long val, void *v)
extern int register_memory_notifier(struct notifier_block *nb);
extern void unregister_memory_notifier(struct notifier_block *nb);
int create_memory_block_devices(unsigned long start, unsigned long size,
- unsigned long vmemmap_pages);
+ unsigned long vmemmap_pages,
+ struct memory_group *group);
void remove_memory_block_devices(unsigned long start, unsigned long size);
extern void memory_dev_init(void);
extern int memory_notify(unsigned long val, void *v);
@@ -96,6 +135,11 @@ extern int walk_memory_blocks(unsigned long start, unsigned long size,
void *arg, walk_memory_blocks_func_t func);
extern int for_each_memory_block(void *arg, walk_memory_blocks_func_t func);
#define CONFIG_MEM_BLOCK_SIZE (PAGES_PER_SECTION<<PAGE_SHIFT)
+
+extern int memory_group_register_static(int nid, unsigned long max_pages);
+extern int memory_group_register_dynamic(int nid, unsigned long unit_pages);
+extern int memory_group_unregister(int mgid);
+struct memory_group *memory_group_find_by_id(int mgid);
#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
#ifdef CONFIG_MEMORY_HOTPLUG
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 39b04e99a30e..5d341978b4bc 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -50,6 +50,11 @@ typedef int __bitwise mhp_t;
* Only selected architectures support it with SPARSE_VMEMMAP.
*/
#define MHP_MEMMAP_ON_MEMORY ((__force mhp_t)BIT(1))
+/*
+ * The nid field specifies a memory group id (mgid) instead. The memory group
+ * implies the node id (nid).
+ */
+#define MHP_NID_IS_MGID ((__force mhp_t)BIT(2))
/*
* Extended parameters for memory hotplug: