With memmap on memory, some architecture needs more details w.r.t altmap
such as base_pfn, end_pfn, etc to unmap vmemmap memory. Instead of
computing them again when we remove a memory block, embed vmem_altmap
details in struct memory_block if we are using memmap on memory block
feature.
Acked-by: Michal Hocko <mho...@suse.com>
Acked-by: David Hildenbrand <da...@redhat.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com>
---
drivers/base/memory.c | 27 +++++++++++++--------
include/linux/memory.h | 8 ++-----
mm/memory_hotplug.c | 54 ++++++++++++++++++++++++++----------------
3 files changed, 52 insertions(+), 37 deletions(-)
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index b456ac213610..8191709c9ad2 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -105,7 +105,8 @@ EXPORT_SYMBOL(unregister_memory_notifier);
static void memory_block_release(struct device *dev)
{
struct memory_block *mem = to_memory_block(dev);
-
+ /* Verify that the altmap is freed */
+ WARN_ON(mem->altmap);
kfree(mem);
}
@@ -183,7 +184,7 @@ static int memory_block_online(struct memory_block *mem)
{
unsigned long start_pfn = section_nr_to_pfn(mem->start_section_nr);
unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;
- unsigned long nr_vmemmap_pages = mem->nr_vmemmap_pages;
+ unsigned long nr_vmemmap_pages = 0;
struct zone *zone;
int ret;
@@ -200,6 +201,9 @@ static int memory_block_online(struct memory_block *mem)
* stage helps to keep accounting easier to follow - e.g vmemmaps
* belong to the same zone as the memory they backed.
*/
+ if (mem->altmap)
+ nr_vmemmap_pages = mem->altmap->free;
+
if (nr_vmemmap_pages) {
ret = mhp_init_memmap_on_memory(start_pfn, nr_vmemmap_pages,
zone);
if (ret)
@@ -230,7 +234,7 @@ static int memory_block_offline(struct memory_block *mem)
{
unsigned long start_pfn = section_nr_to_pfn(mem->start_section_nr);
unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;
- unsigned long nr_vmemmap_pages = mem->nr_vmemmap_pages;
+ unsigned long nr_vmemmap_pages = 0;
int ret;
if (!mem->zone)
@@ -240,6 +244,9 @@ static int memory_block_offline(struct memory_block *mem)
* Unaccount before offlining, such that unpopulated zone and kthreads
* can properly be torn down in offline_pages().
*/
+ if (mem->altmap)
+ nr_vmemmap_pages = mem->altmap->free;
+
if (nr_vmemmap_pages)
adjust_present_page_count(pfn_to_page(start_pfn), mem->group,
-nr_vmemmap_pages);
@@ -726,7 +733,7 @@ void memory_block_add_nid(struct memory_block *mem, int nid,
#endif
static int add_memory_block(unsigned long block_id, unsigned long state,
- unsigned long nr_vmemmap_pages,
+ struct vmem_altmap *altmap,
struct memory_group *group)
{
struct memory_block *mem;
@@ -744,7 +751,7 @@ static int add_memory_block(unsigned long block_id,
unsigned long state,
mem->start_section_nr = block_id * sections_per_block;
mem->state = state;
mem->nid = NUMA_NO_NODE;
- mem->nr_vmemmap_pages = nr_vmemmap_pages;
+ mem->altmap = altmap;
INIT_LIST_HEAD(&mem->group_next);
#ifndef CONFIG_NUMA
@@ -783,14 +790,14 @@ static int __init add_boot_memory_block(unsigned long
base_section_nr)
if (section_count == 0)
return 0;
return add_memory_block(memory_block_id(base_section_nr),
- MEM_ONLINE, 0, NULL);
+ MEM_ONLINE, NULL, NULL);
}
static int add_hotplug_memory_block(unsigned long block_id,
- unsigned long nr_vmemmap_pages,
+ struct vmem_altmap *altmap,
struct memory_group *group)
{
- return add_memory_block(block_id, MEM_OFFLINE, nr_vmemmap_pages, group);
+ return add_memory_block(block_id, MEM_OFFLINE, altmap, group);
}
static void remove_memory_block(struct memory_block *memory)
@@ -818,7 +825,7 @@ static void remove_memory_block(struct memory_block *memory)
* Called under device_hotplug_lock.
*/
int create_memory_block_devices(unsigned long start, unsigned long size,
- unsigned long vmemmap_pages,
+ struct vmem_altmap *altmap,
struct memory_group *group)
{
const unsigned long start_block_id = pfn_to_block_id(PFN_DOWN(start));
@@ -832,7 +839,7 @@ 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 = add_hotplug_memory_block(block_id, vmemmap_pages, group);
+ ret = add_hotplug_memory_block(block_id, altmap, group);
if (ret)
break;
}
diff --git a/include/linux/memory.h b/include/linux/memory.h
index 31343566c221..f53cfdaaaa41 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -77,11 +77,7 @@ struct memory_block {
*/
struct zone *zone;
struct device dev;
- /*
- * Number of vmemmap pages. These pages
- * lay at the beginning of the memory block.
- */
- unsigned long nr_vmemmap_pages;
+ struct vmem_altmap *altmap;
struct memory_group *group; /* group (if any) for this block */
struct list_head group_next; /* next block inside memory group */
#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG)
@@ -147,7 +143,7 @@ static inline int hotplug_memory_notifier(notifier_fn_t fn,
int pri)
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,
+ struct vmem_altmap *altmap,
struct memory_group *group);
void remove_memory_block_devices(unsigned long start, unsigned long size);
extern void memory_dev_init(void);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 76b813991bdc..f8d3e7427e32 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1439,7 +1439,11 @@ int __ref add_memory_resource(int nid, struct resource
*res, mhp_t mhp_flags)
if (mhp_flags & MHP_MEMMAP_ON_MEMORY) {
if (mhp_supports_memmap_on_memory(size)) {
mhp_altmap.free = memory_block_memmap_on_memory_pages();
- params.altmap = &mhp_altmap;
+ params.altmap = kmalloc(sizeof(struct vmem_altmap),
GFP_KERNEL);
+ if (!params.altmap)
+ goto error;
+
+ memcpy(params.altmap, &mhp_altmap, sizeof(mhp_altmap));
}
/* fallback to not using altmap */
}
@@ -1447,13 +1451,13 @@ int __ref add_memory_resource(int nid, struct resource
*res, mhp_t mhp_flags)
/* call arch's memory hotadd */
ret = arch_add_memory(nid, start, size, ¶ms);
if (ret < 0)
- goto error;
+ goto error_free;
/* create memory block devices after memory was added */
- ret = create_memory_block_devices(start, size, mhp_altmap.free, group);
+ ret = create_memory_block_devices(start, size, params.altmap, group);
if (ret) {
arch_remove_memory(start, size, NULL);
- goto error;
+ goto error_free;
}
if (new_node) {
@@ -1490,6 +1494,8 @@ int __ref add_memory_resource(int nid, struct resource
*res, mhp_t mhp_flags)
walk_memory_blocks(start, size, NULL, online_memory_block);
return ret;
+error_free:
+ kfree(params.altmap);
error:
if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK))
memblock_remove(start, size);
@@ -2056,12 +2062,18 @@ static int check_memblock_offlined_cb(struct
memory_block *mem, void *arg)
return 0;
}
-static int get_nr_vmemmap_pages_cb(struct memory_block *mem, void *arg)
+static int test_has_altmap_cb(struct memory_block *mem, void *arg)
{
+ struct memory_block **mem_ptr = (struct memory_block **)arg;
/*
- * If not set, continue with the next block.
+ * return the memblock if we have altmap
+ * and break callback.
*/
- return mem->nr_vmemmap_pages;
+ if (mem->altmap) {
+ *mem_ptr = mem;
+ return 1;
+ }
+ return 0;
}
static int check_cpu_on_node(int nid)
@@ -2136,10 +2148,9 @@ EXPORT_SYMBOL(try_offline_node);
static int __ref try_remove_memory(u64 start, u64 size)
{
- struct vmem_altmap mhp_altmap = {};
- struct vmem_altmap *altmap = NULL;
- unsigned long nr_vmemmap_pages;
+ struct memory_block *mem;
int rc = 0, nid = NUMA_NO_NODE;
+ struct vmem_altmap *altmap = NULL;
BUG_ON(check_hotplug_memory_range(start, size));
@@ -2161,25 +2172,20 @@ static int __ref try_remove_memory(u64 start, u64 size)
* the same granularity it was added - a single memory block.
*/
if (mhp_memmap_on_memory()) {
- nr_vmemmap_pages = walk_memory_blocks(start, size, NULL,
- get_nr_vmemmap_pages_cb);
- if (nr_vmemmap_pages) {
+ rc = walk_memory_blocks(start, size, &mem, test_has_altmap_cb);
+ if (rc) {
if (size != memory_block_size_bytes()) {
pr_warn("Refuse to remove %#llx - %#llx,"
"wrong granularity\n",
start, start + size);
return -EINVAL;
}
-
+ altmap = mem->altmap;
/*
- * Let remove_pmd_table->free_hugepage_table do the
- * right thing if we used vmem_altmap when hot-adding
- * the range.
+ * Mark altmap NULL so that we can add a debug
+ * check on memblock free.
*/
- mhp_altmap.base_pfn = PHYS_PFN(start);
- mhp_altmap.free = nr_vmemmap_pages;
- mhp_altmap.alloc = nr_vmemmap_pages;
- altmap = &mhp_altmap;
+ mem->altmap = NULL;
}
}
@@ -2196,6 +2202,12 @@ static int __ref try_remove_memory(u64 start, u64 size)
arch_remove_memory(start, size, altmap);
+ /* Verify that all vmemmap pages have actually been freed. */
+ if (altmap) {
+ WARN(altmap->alloc, "Altmap not fully unmapped");
+ kfree(altmap);
+ }
+
if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) {
memblock_phys_free(start, size);
memblock_remove(start, size);
--
2.41.0
