Backport version to the 5.4-stable tree of the commit:
f85086f95fa3 ("mm: don't rely on system state to detect hot-plug operations")
Cc: stable@xxxxxxxxxxxxxxx # 4.19.y
Signed-off-by: Laurent Dufour <ldufour@xxxxxxxxxxxxx>
---
drivers/base/node.c | 84 ++++++++++++++++++++++++++++----------------
include/linux/node.h | 11 +++---
mm/memory_hotplug.c | 3 +-
3 files changed, 63 insertions(+), 35 deletions(-)
diff --git a/drivers/base/node.c b/drivers/base/node.c
index f3565c2dbc52..503e2f90e58e 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -403,10 +403,32 @@ static int __ref get_nid_for_pfn(unsigned long pfn)
return pfn_to_nid(pfn);
}
+static int do_register_memory_block_under_node(int nid,
+ struct memory_block *mem_blk)
+{
+ int ret;
+
+ /*
+ * If this memory block spans multiple nodes, we only indicate
+ * the last processed node.
+ */
+ mem_blk->nid = nid;
+
+ ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj,
+ &mem_blk->dev.kobj,
+ kobject_name(&mem_blk->dev.kobj));
+ if (ret)
+ return ret;
+
+ return sysfs_create_link_nowarn(&mem_blk->dev.kobj,
+ &node_devices[nid]->dev.kobj,
+ kobject_name(&node_devices[nid]->dev.kobj));
+}
+
/* register memory section under specified node if it spans that node */
-int register_mem_sect_under_node(struct memory_block *mem_blk, void *arg)
+int register_mem_block_under_node_early(struct memory_block *mem_blk, void *arg)
{
- int ret, nid = *(int *)arg;
+ int nid = *(int *)arg;
unsigned long pfn, sect_start_pfn, sect_end_pfn;
sect_start_pfn = section_nr_to_pfn(mem_blk->start_section_nr);
@@ -426,38 +448,33 @@ int register_mem_sect_under_node(struct memory_block *mem_blk, void *arg)
}
/*
- * We need to check if page belongs to nid only for the boot
- * case, during hotplug we know that all pages in the memory
- * block belong to the same node.
- */
- if (system_state == SYSTEM_BOOTING) {
- page_nid = get_nid_for_pfn(pfn);
- if (page_nid < 0)
- continue;
- if (page_nid != nid)
- continue;
- }
-
- /*
- * If this memory block spans multiple nodes, we only indicate
- * the last processed node.
+ * We need to check if page belongs to nid only at the boot
+ * case because node's ranges can be interleaved.
*/
- mem_blk->nid = nid;
-
- ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj,
- &mem_blk->dev.kobj,
- kobject_name(&mem_blk->dev.kobj));
- if (ret)
- return ret;
+ page_nid = get_nid_for_pfn(pfn);
+ if (page_nid < 0)
+ continue;
+ if (page_nid != nid)
+ continue;
- return sysfs_create_link_nowarn(&mem_blk->dev.kobj,
- &node_devices[nid]->dev.kobj,
- kobject_name(&node_devices[nid]->dev.kobj));
+ return do_register_memory_block_under_node(nid, mem_blk);
}
/* mem section does not span the specified node */
return 0;
}
+/*
+ * During hotplug we know that all pages in the memory block belong to the same
+ * node.
+ */
+static int register_mem_block_under_node_hotplug(struct memory_block *mem_blk,
+ void *arg)
+{
+ int nid = *(int *)arg;
+
+ return do_register_memory_block_under_node(nid, mem_blk);
+}
+
/*
* Unregister a memory block device under the node it spans. Memory blocks
* with multiple nodes cannot be offlined and therefore also never be removed.
@@ -473,10 +490,17 @@ void unregister_memory_block_under_nodes(struct memory_block *mem_blk)
kobject_name(&node_devices[mem_blk->nid]->dev.kobj));
}
-int link_mem_sections(int nid, unsigned long start_pfn, unsigned long end_pfn)
+int link_mem_sections(int nid, unsigned long start_pfn, unsigned long end_pfn,
+ enum meminit_context context)
{
- return walk_memory_range(start_pfn, end_pfn, (void *)&nid,
- register_mem_sect_under_node);
+ walk_memory_blocks_func_t func;
+
+ if (context == MEMINIT_HOTPLUG)
+ func = register_mem_block_under_node_hotplug;
+ else
+ func = register_mem_block_under_node_early;
+
+ return walk_memory_range(start_pfn, end_pfn, (void *)&nid, func);
}
#ifdef CONFIG_HUGETLBFS
diff --git a/include/linux/node.h b/include/linux/node.h
index 708939bae9aa..a79ec4492650 100644
--- a/include/linux/node.h
+++ b/include/linux/node.h
@@ -32,11 +32,13 @@ extern struct node *node_devices[];
typedef void (*node_registration_func_t)(struct node *);
#if defined(CONFIG_MEMORY_HOTPLUG_SPARSE) && defined(CONFIG_NUMA)
-extern int link_mem_sections(int nid, unsigned long start_pfn,
- unsigned long end_pfn);
+int link_mem_sections(int nid, unsigned long start_pfn,
+ unsigned long end_pfn,
+ enum meminit_context context);
#else
static inline int link_mem_sections(int nid, unsigned long start_pfn,
- unsigned long end_pfn)
+ unsigned long end_pfn,
+ enum meminit_context context)
{
return 0;
}
@@ -61,7 +63,8 @@ static inline int register_one_node(int nid)
if (error)
return error;
/* link memory sections under this node */
- error = link_mem_sections(nid, start_pfn, end_pfn);
+ error = link_mem_sections(nid, start_pfn, end_pfn,
+ MEMINIT_EARLY);
}
return error;
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index c839c4ad4871..e60e28131f67 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1102,7 +1102,8 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online)
}
/* link memory sections under this node.*/
- ret = link_mem_sections(nid, PFN_DOWN(start), PFN_UP(start + size - 1));
+ ret = link_mem_sections(nid, PFN_DOWN(start), PFN_UP(start + size - 1),
+ MEMINIT_HOTPLUG);
BUG_ON(ret);
/* create new memmap entry */
--
2.28.0
