Since commit c5e79ef561b0 ("mm/memory_hotplug.c: don't allow to
online/offline memory blocks with holes") we have a generic check in
offline_pages() that disallows offlining memory blocks with holes.
Memory blocks with missing sections are just another variant of these
type of blocks. We can stop checking (and especially storing) present
sections. A proper error message is now printed why offlining failed.
section_count was initially introduced in commit 07681215975e ("Driver
core: Add section count to memory_block struct") in order to detect
when it is okay to remove a memory block. It was used in commit
26bbe7ef6d5c ("drivers/base/memory.c: prohibit offlining of memory blocks
with missing sections") to disallow offlining memory blocks with missing
sections. As we refactored creation/removal of memory devices and have
a proper check for holes in place, we can drop the section_count.
This also removes a leftover comment regarding the mem_sysfs_mutex,
which was removed in commit 848e19ad3c33 ("drivers/base/memory.c: drop
the mem_sysfs_mutex").
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
drivers/base/memory.c | 17 +++--------------
include/linux/memory.h | 1 -
2 files changed, 3 insertions(+), 15 deletions(-)
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 6503f5d0b749..852fece9be1d 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -292,10 +292,6 @@ static int memory_subsys_offline(struct device *dev)
if (mem->state == MEM_OFFLINE)
return 0;
- /* Can't offline block with non-present sections */
- if (mem->section_count != sections_per_block)
- return -EINVAL;
-
return memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE);
}
@@ -660,7 +656,7 @@ static int init_memory_block(struct memory_block **memory,
static int add_memory_block(unsigned long base_section_nr)
{
- int ret, section_count = 0;
+ int section_count = 0;
struct memory_block *mem;
unsigned long nr;
@@ -671,12 +667,8 @@ static int add_memory_block(unsigned long base_section_nr)
if (section_count == 0)
return 0;
- ret = init_memory_block(&mem, base_memory_block_id(base_section_nr),
- MEM_ONLINE);
- if (ret)
- return ret;
- mem->section_count = section_count;
- return 0;
+ return init_memory_block(&mem, base_memory_block_id(base_section_nr),
+ MEM_ONLINE);
}
static void unregister_memory(struct memory_block *memory)
@@ -714,7 +706,6 @@ int create_memory_block_devices(unsigned long start, unsigned long size)
ret = init_memory_block(&mem, block_id, MEM_OFFLINE);
if (ret)
break;
- mem->section_count = sections_per_block;
}
if (ret) {
end_block_id = block_id;
@@ -723,7 +714,6 @@ int create_memory_block_devices(unsigned long start, unsigned long size)
mem = find_memory_block_by_id(block_id);
if (WARN_ON_ONCE(!mem))
continue;
- mem->section_count = 0;
unregister_memory(mem);
}
}
@@ -752,7 +742,6 @@ void remove_memory_block_devices(unsigned long start, unsigned long size)
mem = find_memory_block_by_id(block_id);
if (WARN_ON_ONCE(!mem))
continue;
- mem->section_count = 0;
unregister_memory_block_under_nodes(mem);
unregister_memory(mem);
}
diff --git a/include/linux/memory.h b/include/linux/memory.h
index 0b8d791b6669..439a89e758d8 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -26,7 +26,6 @@
struct memory_block {
unsigned long start_section_nr;
unsigned long state; /* serialized by the dev->lock */
- int section_count; /* serialized by mem_sysfs_mutex */
int online_type; /* for passing data to online routine */
int phys_device; /* to which fru does this belong? */
struct device dev;
--
2.24.1
