The patch titled
Subject: mm/memory_hotplug.c: clean up unregister_mem_sect_under_nodes()
has been added to the -mm tree. Its filename is
mm-memory_hotplug-cleanup-unregister_mem_sect_under_nodes.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-memory_hotplug-cleanup-unregister_mem_sect_under_nodes.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-memory_hotplug-cleanup-unregister_mem_sect_under_nodes.patch
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------------------------------------------------------
From: Oscar Salvador <osalvador@xxxxxxx>
Subject: mm/memory_hotplug.c: clean up unregister_mem_sect_under_nodes()
With the assumption that the relationship between memory_block <-> node is
1:1, we can refactor this function a bit.
This assumption is being taken from register_mem_sect_under_node() code.
register_mem_sect_under_node() takes the mem_blk's nid, and compares it to
the pfn's nid we are checking. If they match, we go ahead and link both
objects. Once done, we just return.
So the relationship between memory_block <-> node seems to stand.
Currently, unregister_mem_sect_under_nodes() defines a nodemask_t which is
being checked in the loop to see if we have already unlinked a certain
node. But since a memory_block can only belong to a single node, we can
drop the nodemask and the check within the loop.
If we find a match between the mem_block->nid and the nid of the pfn we
are checking, we unlink the objects and return, as unlinking the objects
once is enough.
Link: http://lkml.kernel.org/r/20180810152931.23004-4-osalvador@xxxxxxxxxxxxxxxxxx
Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Jonathan Cameron <jonathan.cameron@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: <yasu.isimatu@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/base/node.c | 30 +++++++++++-------------------
1 file changed, 11 insertions(+), 19 deletions(-)
--- a/drivers/base/node.c~mm-memory_hotplug-cleanup-unregister_mem_sect_under_nodes
+++ a/drivers/base/node.c
@@ -448,35 +448,27 @@ int register_mem_sect_under_node(struct
return 0;
}
-/* unregister memory section under all nodes that it spans */
+/* unregister memory section from the node it belongs to */
int unregister_mem_sect_under_nodes(struct memory_block *mem_blk,
unsigned long phys_index)
{
- NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL);
unsigned long pfn, sect_start_pfn, sect_end_pfn;
-
- if (!unlinked_nodes)
- return -ENOMEM;
- nodes_clear(*unlinked_nodes);
+ int nid = mem_blk->nid;
sect_start_pfn = section_nr_to_pfn(phys_index);
sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
- int nid;
+ int page_nid = get_nid_for_pfn(pfn);
- nid = get_nid_for_pfn(pfn);
- if (nid < 0)
- continue;
- if (!node_online(nid))
- continue;
- if (node_test_and_set(nid, *unlinked_nodes))
- continue;
- sysfs_remove_link(&node_devices[nid]->dev.kobj,
- kobject_name(&mem_blk->dev.kobj));
- sysfs_remove_link(&mem_blk->dev.kobj,
- kobject_name(&node_devices[nid]->dev.kobj));
+ if (page_nid >= 0 && page_nid == nid) {
+ sysfs_remove_link(&node_devices[nid]->dev.kobj,
+ kobject_name(&mem_blk->dev.kobj));
+ sysfs_remove_link(&mem_blk->dev.kobj,
+ kobject_name(&node_devices[nid]->dev.kobj));
+ break;
+ }
}
- NODEMASK_FREE(unlinked_nodes);
+
return 0;
}
_
Patches currently in -mm which might be from osalvador@xxxxxxx are
mm-memory_hotplug-make-add_memory_resource-use-__try_online_node.patch
mm-memory_hotplug-call-register_mem_sect_under_node.patch
mm-memory_hotplug-make-register_mem_sect_under_node-a-cb-of-walk_memory_range.patch
mm-memory_hotplug-drop-unnecessary-checks-from-register_mem_sect_under_node.patch
mm-sparse-make-sparse_init_one_section-void-and-remove-check.patch
mm-remove-zone_id-and-make-use-of-zone_idx-in-is_dev_zone.patch
mm-page_alloc-move-ifdefery-out-of-free_area_init_core.patch
mm-page_alloc-inline-function-to-handle-config_deferred_struct_page_init.patch
mm-page_alloc-introduce-free_area_init_core_hotplug.patch
mm-page_alloc-introduce-free_area_init_core_hotplug-v6.patch
mm-memory_hotplug-drop-unused-args-from-remove_memory_section.patch
mm-memory_hotplug-drop-unneeded-check-from-unregister_mem_sect_under_nodes.patch
mm-memory_hotplug-cleanup-unregister_mem_sect_under_nodes.patch
