From: Wen Congyang <wency@xxxxxxxxxxxxxx>
The function offline_memory() will be called when hot removing a
memory device. The memory device may contain more than one memory
block. If the memory block has been offlined, __offline_pages()
will fail. So we should try to offline one memory block at a
time.
If the memory block is offlined in offline_memory(), we also
update it's state, and notify the userspace that its state is
changed.
The function offline_memory() also check each memory block's
state. So there is no need to check the memory block's state
before calling offline_memory().
CC: David Rientjes <rientjes@xxxxxxxxxx>
CC: Jiang Liu <liuj97@xxxxxxxxx>
CC: Len Brown <len.brown@xxxxxxxxx>
CC: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
CC: Paul Mackerras <paulus@xxxxxxxxx>
CC: Christoph Lameter <cl@xxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
CC: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
CC: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
CC: Vasilis Liaskovitis <vasilis.liaskovitis@xxxxxxxxxxxxxxxx>
Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx>
---
drivers/base/memory.c | 31 +++++++++++++++++++++++++++----
include/linux/memory_hotplug.h | 2 ++
mm/memory_hotplug.c | 37 ++++++++++++++++++++++++++++++++++++-
3 files changed, 65 insertions(+), 5 deletions(-)
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 44e7de6..86c8821 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -275,13 +275,11 @@ memory_block_action(unsigned long phys_index, unsigned long action)
return ret;
}
-static int memory_block_change_state(struct memory_block *mem,
+static int __memory_block_change_state(struct memory_block *mem,
unsigned long to_state, unsigned long from_state_req)
{
int ret = 0;
- mutex_lock(&mem->state_mutex);
-
if (mem->state != from_state_req) {
ret = -EINVAL;
goto out;
@@ -309,10 +307,20 @@ static int memory_block_change_state(struct memory_block *mem,
break;
}
out:
- mutex_unlock(&mem->state_mutex);
return ret;
}
+static int memory_block_change_state(struct memory_block *mem,
+ unsigned long to_state, unsigned long from_state_req)
+{
+ int ret;
+
+ mutex_lock(&mem->state_mutex);
+ ret = __memory_block_change_state(mem, to_state, from_state_req);
+ mutex_unlock(&mem->state_mutex);
+
+ return ret;
+}
static ssize_t
store_mem_state(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
@@ -653,6 +661,21 @@ int unregister_memory_section(struct mem_section *section)
}
/*
+ * offline one memory block. If the memory block has been offlined, do nothing.
+ */
+int offline_memory_block(struct memory_block *mem)
+{
+ int ret = 0;
+
+ mutex_lock(&mem->state_mutex);
+ if (mem->state != MEM_OFFLINE)
+ ret = __memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE);
+ mutex_unlock(&mem->state_mutex);
+
+ return ret;
+}
+
+/*
* Initialize the sysfs support for memory devices...
*/
int __init memory_dev_init(void)
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index c183f39..0b040bb 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -10,6 +10,7 @@ struct page;
struct zone;
struct pglist_data;
struct mem_section;
+struct memory_block;
#ifdef CONFIG_MEMORY_HOTPLUG
@@ -234,6 +235,7 @@ extern int mem_online_node(int nid);
extern int add_memory(int nid, u64 start, u64 size);
extern int arch_add_memory(int nid, u64 start, u64 size);
extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages);
+extern int offline_memory_block(struct memory_block *mem);
extern int offline_memory(u64 start, u64 size);
extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
int nr_pages);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index c182c76..3113cd4 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1001,7 +1001,42 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
int offline_memory(u64 start, u64 size)
{
- return -EINVAL;
+ struct memory_block *mem = NULL;
+ struct mem_section *section;
+ unsigned long start_pfn, end_pfn;
+ unsigned long pfn, section_nr;
+ int ret;
+
+ start_pfn = PFN_DOWN(start);
+ end_pfn = start_pfn + PFN_DOWN(size);
+
+ for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
+ section_nr = pfn_to_section_nr(pfn);
+ if (!present_section_nr(section_nr))
+ continue;
+
+ section = __nr_to_section(section_nr);
+ /* same memblock? */
+ if (mem)
+ if ((section_nr >= mem->start_section_nr) &&
+ (section_nr <= mem->end_section_nr))
+ continue;
+
+ mem = find_memory_block_hinted(section, mem);
+ if (!mem)
+ continue;
+
+ ret = offline_memory_block(mem);
+ if (ret) {
+ kobject_put(&mem->dev.kobj);
+ return ret;
+ }
+ }
+
+ if (mem)
+ kobject_put(&mem->dev.kobj);
+
+ return 0;
}
#else
int offline_pages(u64 start, u64 size)
--
1.7.1
--
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