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authorDavid Hildenbrand <david@redhat.com>2021-09-07 19:55:26 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-09-08 11:50:23 -0700
commit028fc57a1c361116e3bcebfeba4ca87878baaf4f (patch)
tree65f2e2e44292b89807668774829b5758d13d4a76 /drivers
parente83a437faa625efb2e70924fd3c32ba95610c502 (diff)
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 'drivers')
-rw-r--r--drivers/base/memory.c159
1 files changed, 155 insertions, 4 deletions
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 86ec2dc82fc2..16f5a3610229 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -82,6 +82,11 @@ static struct bus_type memory_subsys = {
*/
static DEFINE_XARRAY(memory_blocks);
+/*
+ * Memory groups, indexed by memory group id (mgid).
+ */
+static DEFINE_XARRAY_FLAGS(memory_groups, XA_FLAGS_ALLOC);
+
static BLOCKING_NOTIFIER_HEAD(memory_chain);
int register_memory_notifier(struct notifier_block *nb)
@@ -634,7 +639,8 @@ int register_memory(struct memory_block *memory)
}
static int init_memory_block(unsigned long block_id, unsigned long state,
- unsigned long nr_vmemmap_pages)
+ unsigned long nr_vmemmap_pages,
+ struct memory_group *group)
{
struct memory_block *mem;
int ret = 0;
@@ -652,6 +658,12 @@ static int init_memory_block(unsigned long block_id, unsigned long state,
mem->state = state;
mem->nid = NUMA_NO_NODE;
mem->nr_vmemmap_pages = nr_vmemmap_pages;
+ INIT_LIST_HEAD(&mem->group_next);
+
+ if (group) {
+ mem->group = group;
+ list_add(&mem->group_next, &group->memory_blocks);
+ }
ret = register_memory(mem);
@@ -671,7 +683,7 @@ static int add_memory_block(unsigned long base_section_nr)
if (section_count == 0)
return 0;
return init_memory_block(memory_block_id(base_section_nr),
- MEM_ONLINE, 0);
+ MEM_ONLINE, 0, NULL);
}
static void unregister_memory(struct memory_block *memory)
@@ -681,6 +693,11 @@ static void unregister_memory(struct memory_block *memory)
WARN_ON(xa_erase(&memory_blocks, memory->dev.id) == NULL);
+ if (memory->group) {
+ list_del(&memory->group_next);
+ memory->group = NULL;
+ }
+
/* drop the ref. we got via find_memory_block() */
put_device(&memory->dev);
device_unregister(&memory->dev);
@@ -694,7 +711,8 @@ static void unregister_memory(struct memory_block *memory)
* Called under device_hotplug_lock.
*/
int create_memory_block_devices(unsigned long start, unsigned long size,
- unsigned long vmemmap_pages)
+ unsigned long vmemmap_pages,
+ struct memory_group *group)
{
const unsigned long start_block_id = pfn_to_block_id(PFN_DOWN(start));
unsigned long end_block_id = pfn_to_block_id(PFN_DOWN(start + size));
@@ -707,7 +725,8 @@ int create_memory_block_devices(unsigned long start, unsigned long size,
return -EINVAL;
for (block_id = start_block_id; block_id != end_block_id; block_id++) {
- ret = init_memory_block(block_id, MEM_OFFLINE, vmemmap_pages);
+ ret = init_memory_block(block_id, MEM_OFFLINE, vmemmap_pages,
+ group);
if (ret)
break;
}
@@ -891,3 +910,135 @@ int for_each_memory_block(void *arg, walk_memory_blocks_func_t func)
return bus_for_each_dev(&memory_subsys, NULL, &cb_data,
for_each_memory_block_cb);
}
+
+/*
+ * This is an internal helper to unify allocation and initialization of
+ * memory groups. Note that the passed memory group will be copied to a
+ * dynamically allocated memory group. After this call, the passed
+ * memory group should no longer be used.
+ */
+static int memory_group_register(struct memory_group group)
+{
+ struct memory_group *new_group;
+ uint32_t mgid;
+ int ret;
+
+ if (!node_possible(group.nid))
+ return -EINVAL;
+
+ new_group = kzalloc(sizeof(group), GFP_KERNEL);
+ if (!new_group)
+ return -ENOMEM;
+ *new_group = group;
+ INIT_LIST_HEAD(&new_group->memory_blocks);
+
+ ret = xa_alloc(&memory_groups, &mgid, new_group, xa_limit_31b,
+ GFP_KERNEL);
+ if (ret) {
+ kfree(new_group);
+ return ret;
+ }
+ return mgid;
+}
+
+/**
+ * memory_group_register_static() - Register a static memory group.
+ * @nid: The node id.
+ * @max_pages: The maximum number of pages we'll have in this static memory
+ * group.
+ *
+ * Register a new static memory group and return the memory group id.
+ * All memory in the group belongs to a single unit, such as a DIMM. All
+ * memory belonging to a static memory group is added in one go to be removed
+ * in one go -- it's static.
+ *
+ * Returns an error if out of memory, if the node id is invalid, if no new
+ * memory groups can be registered, or if max_pages is invalid (0). Otherwise,
+ * returns the new memory group id.
+ */
+int memory_group_register_static(int nid, unsigned long max_pages)
+{
+ struct memory_group group = {
+ .nid = nid,
+ .s = {
+ .max_pages = max_pages,
+ },
+ };
+
+ if (!max_pages)
+ return -EINVAL;
+ return memory_group_register(group);
+}
+EXPORT_SYMBOL_GPL(memory_group_register_static);
+
+/**
+ * memory_group_register_dynamic() - Register a dynamic memory group.
+ * @nid: The node id.
+ * @unit_pages: Unit in pages in which is memory added/removed in this dynamic
+ * memory group.
+ *
+ * Register a new dynamic memory group and return the memory group id.
+ * Memory within a dynamic memory group is added/removed dynamically
+ * in unit_pages.
+ *
+ * Returns an error if out of memory, if the node id is invalid, if no new
+ * memory groups can be registered, or if unit_pages is invalid (0, not a
+ * power of two, smaller than a single memory block). Otherwise, returns the
+ * new memory group id.
+ */
+int memory_group_register_dynamic(int nid, unsigned long unit_pages)
+{
+ struct memory_group group = {
+ .nid = nid,
+ .is_dynamic = true,
+ .d = {
+ .unit_pages = unit_pages,
+ },
+ };
+
+ if (!unit_pages || !is_power_of_2(unit_pages) ||
+ unit_pages < PHYS_PFN(memory_block_size_bytes()))
+ return -EINVAL;
+ return memory_group_register(group);
+}
+EXPORT_SYMBOL_GPL(memory_group_register_dynamic);
+
+/**
+ * memory_group_unregister() - Unregister a memory group.
+ * @mgid: the memory group id
+ *
+ * Unregister a memory group. If any memory block still belongs to this
+ * memory group, unregistering will fail.
+ *
+ * Returns -EINVAL if the memory group id is invalid, returns -EBUSY if some
+ * memory blocks still belong to this memory group and returns 0 if
+ * unregistering succeeded.
+ */
+int memory_group_unregister(int mgid)
+{
+ struct memory_group *group;
+
+ if (mgid < 0)
+ return -EINVAL;
+
+ group = xa_load(&memory_groups, mgid);
+ if (!group)
+ return -EINVAL;
+ if (!list_empty(&group->memory_blocks))
+ return -EBUSY;
+ xa_erase(&memory_groups, mgid);
+ kfree(group);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(memory_group_unregister);
+
+/*
+ * This is an internal helper only to be used in core memory hotplug code to
+ * lookup a memory group. We don't care about locking, as we don't expect a
+ * memory group to get unregistered while adding memory to it -- because
+ * the group and the memory is managed by the same driver.
+ */
+struct memory_group *memory_group_find_by_id(int mgid)
+{
+ return xa_load(&memory_groups, mgid);
+}