In preparation for sub-section memory hotplug support, remove a
dependency on ->section_mem_map being populated. In SPARSEMEM_VMEMMAP=y
configurations pfn_to_page() does not use ->section_mem_map. The
sub-section hotplug support relies on this fact and skips initializing
it. Without ->section_mem_map populated, or aligned to section boundary,
conversions of mem_section instances to zones is not possible.
So, this removes a false dependency on a structure field that will only
be valid in the SPARSEMEM_VMEMMAP=n case, and only used for
pfn_to_page() (and similar) operations.
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Stephen Bates <stephen.bates@xxxxxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/base/memory.c | 26 +++++++++-----------------
include/linux/memory.h | 4 ++--
mm/memory_hotplug.c | 4 ++--
3 files changed, 13 insertions(+), 21 deletions(-)
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index cc4f1d0cbffe..2cf8e97c15ce 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -685,24 +685,16 @@ static int add_memory_block(int base_section_nr)
return 0;
}
-static bool is_zone_device_section(struct mem_section *ms)
-{
- struct page *page;
-
- page = sparse_decode_mem_map(ms->section_mem_map, __section_nr(ms));
- return is_zone_device_page(page);
-}
-
/*
* need an interface for the VM to add new memory regions,
* but without onlining it.
*/
-int register_new_memory(int nid, struct mem_section *section)
+int register_new_memory(struct zone *zone, int nid, struct mem_section *section)
{
int ret = 0;
struct memory_block *mem;
- if (is_zone_device_section(section))
+ if (is_dev_zone(zone))
return 0;
mutex_lock(&mem_sysfs_mutex);
@@ -736,14 +728,11 @@ unregister_memory(struct memory_block *memory)
device_unregister(&memory->dev);
}
-static int remove_memory_section(unsigned long node_id,
- struct mem_section *section, int phys_device)
+static int remove_memory_section(struct zone *zone, unsigned long node_id,
+ struct mem_section *section, int phys_device)
{
struct memory_block *mem;
- if (is_zone_device_section(section))
- return 0;
-
mutex_lock(&mem_sysfs_mutex);
mem = find_memory_block(section);
unregister_mem_sect_under_nodes(mem, __section_nr(section));
@@ -758,12 +747,15 @@ static int remove_memory_section(unsigned long node_id,
return 0;
}
-int unregister_memory_section(struct mem_section *section)
+int unregister_memory_section(struct zone *zone, struct mem_section *section)
{
+ if (is_dev_zone(zone))
+ return 0;
+
if (!present_section(section))
return -EINVAL;
- return remove_memory_section(0, section, 0);
+ return remove_memory_section(zone, 0, section, 0);
}
#endif /* CONFIG_MEMORY_HOTREMOVE */
diff --git a/include/linux/memory.h b/include/linux/memory.h
index b723a686fc10..e42df1abcb55 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -108,9 +108,9 @@ extern int register_memory_notifier(struct notifier_block *nb);
extern void unregister_memory_notifier(struct notifier_block *nb);
extern int register_memory_isolate_notifier(struct notifier_block *nb);
extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
-extern int register_new_memory(int, struct mem_section *);
+extern int register_new_memory(struct zone *, int, struct mem_section *);
#ifdef CONFIG_MEMORY_HOTREMOVE
-extern int unregister_memory_section(struct mem_section *);
+extern int unregister_memory_section(struct zone *, struct mem_section *);
#endif
extern int memory_dev_init(void);
extern int memory_notify(unsigned long val, void *v);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 07accab8441d..dc6f815c2d37 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -524,7 +524,7 @@ static int __meminit __add_section(int nid, struct zone *zone,
if (ret < 0)
return ret;
- return register_new_memory(nid, __pfn_to_section(phys_start_pfn));
+ return register_new_memory(zone, nid, __pfn_to_section(phys_start_pfn));
}
/*
@@ -791,7 +791,7 @@ static int __remove_section(struct zone *zone, struct mem_section *ms,
if (!valid_section(ms))
return ret;
- ret = unregister_memory_section(ms);
+ ret = unregister_memory_section(zone, ms);
if (ret)
return ret;
--
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