[RFC PATCH v4 2/13] memory-hotplug : add physical memory hotplug code to acpi_memory_device_remove
Yasuaki Ishimatsu
isimatu.yasuaki at jp.fujitsu.com
Wed Jul 18 20:06:49 EST 2012
acpi_memory_device_remove() has been prepared to remove physical memory.
But, the function only frees acpi_memory_device currentlry.
The patch adds following functions into acpi_memory_device_remove():
- offline memory
- remove physical memory. It only check whether memory is online or not.
- free acpi_memory_device
CC: David Rientjes <rientjes at google.com>
CC: Jiang Liu <liuj97 at gmail.com>
CC: Len Brown <len.brown at intel.com>
CC: Benjamin Herrenschmidt <benh at kernel.crashing.org>
CC: Paul Mackerras <paulus at samba.org>
CC: Christoph Lameter <cl at linux.com>
Cc: Minchan Kim <minchan.kim at gmail.com>
CC: Andrew Morton <akpm at linux-foundation.org>
CC: KOSAKI Motohiro <kosaki.motohiro at jp.fujitsu.com>
CC: Wen Congyang <wency at cn.fujitsu.com>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki at jp.fujitsu.com>
---
drivers/acpi/acpi_memhotplug.c | 27 ++++++++++++++++++++++++++-
drivers/base/memory.c | 39 +++++++++++++++++++++++++++++++++++++++
include/linux/memory.h | 5 +++++
include/linux/memory_hotplug.h | 5 +++++
mm/memory_hotplug.c | 22 ++++++++++++++++++++++
5 files changed, 97 insertions(+), 1 deletion(-)
Index: linux-3.5-rc6/drivers/acpi/acpi_memhotplug.c
===================================================================
--- linux-3.5-rc6.orig/drivers/acpi/acpi_memhotplug.c 2012-07-17 11:20:15.117796971 +0900
+++ linux-3.5-rc6/drivers/acpi/acpi_memhotplug.c 2012-07-17 13:36:30.325594022 +0900
@@ -29,6 +29,7 @@
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
+#include <linux/memory.h>
#include <linux/memory_hotplug.h>
#include <linux/slab.h>
#include <acpi/acpi_drivers.h>
@@ -452,12 +453,36 @@ static int acpi_memory_device_add(struct
static int acpi_memory_device_remove(struct acpi_device *device, int type)
{
struct acpi_memory_device *mem_device = NULL;
-
+ struct acpi_memory_info *info, *tmp;
+ int result;
+ int node;
if (!device || !acpi_driver_data(device))
return -EINVAL;
mem_device = acpi_driver_data(device);
+
+ node = acpi_get_node(mem_device->device->handle);
+ list_for_each_entry_safe(info, tmp, &mem_device->res_list, list) {
+ if (!info->enabled)
+ continue;
+
+ if (!is_memblk_offline(info->start_addr, info->length)) {
+ result = offline_memory(info->start_addr, info->length);
+ if (result)
+ return result;
+ }
+ if (node < 0)
+ node = memory_add_physaddr_to_nid(info->start_addr);
+
+ result = remove_memory(node, info->start_addr, info->length);
+ if (result)
+ return result;
+
+ list_del(&info->list);
+ kfree(info);
+ }
+
kfree(mem_device);
return 0;
Index: linux-3.5-rc6/include/linux/memory_hotplug.h
===================================================================
--- linux-3.5-rc6.orig/include/linux/memory_hotplug.h 2012-07-17 11:20:15.133796772 +0900
+++ linux-3.5-rc6/include/linux/memory_hotplug.h 2012-07-17 11:29:41.490716352 +0900
@@ -221,6 +221,7 @@ static inline void unlock_memory_hotplug
#ifdef CONFIG_MEMORY_HOTREMOVE
extern int is_mem_section_removable(unsigned long pfn, unsigned long nr_pages);
+extern int remove_memory(int nid, u64 start, u64 size);
#else
static inline int is_mem_section_removable(unsigned long pfn,
@@ -228,6 +229,10 @@ static inline int is_mem_section_removab
{
return 0;
}
+static inline int remove_memory(int nid, u64 start, u64 size)
+{
+ return -EBUSY;
+}
#endif /* CONFIG_MEMORY_HOTREMOVE */
extern int mem_online_node(int nid);
Index: linux-3.5-rc6/mm/memory_hotplug.c
===================================================================
--- linux-3.5-rc6.orig/mm/memory_hotplug.c 2012-07-17 11:20:15.129796821 +0900
+++ linux-3.5-rc6/mm/memory_hotplug.c 2012-07-17 13:25:18.952986069 +0900
@@ -998,6 +998,28 @@ int offline_memory(u64 start, u64 size)
end_pfn = start_pfn + PFN_DOWN(size);
return offline_pages(start_pfn, end_pfn, 120 * HZ);
}
+
+int remove_memory(int nid, u64 start, u64 size)
+{
+ int ret = -EBUSY;
+ lock_memory_hotplug();
+ /*
+ * The memory might become online by other task, even if you offine it.
+ * So we check whether the cpu has been onlined or not.
+ */
+ if (!is_memblk_offline(start, size)) {
+ pr_warn("memory removing [mem %#010llx-%#010llx] failed, "
+ "because the memmory range is online\n",
+ start, start + size);
+ ret = -EAGAIN;
+ }
+
+ unlock_memory_hotplug();
+ return ret;
+
+}
+EXPORT_SYMBOL_GPL(remove_memory);
+
#else
int offline_memory(u64 start, u64 size)
{
Index: linux-3.5-rc6/drivers/base/memory.c
===================================================================
--- linux-3.5-rc6.orig/drivers/base/memory.c 2012-07-17 11:20:15.120796934 +0900
+++ linux-3.5-rc6/drivers/base/memory.c 2012-07-17 11:20:54.626302995 +0900
@@ -70,6 +70,45 @@ void unregister_memory_isolate_notifier(
}
EXPORT_SYMBOL(unregister_memory_isolate_notifier);
+bool is_memblk_offline(unsigned long start, unsigned long size)
+{
+ struct memory_block *mem = NULL;
+ struct mem_section *section;
+ unsigned long start_pfn, end_pfn;
+ unsigned long pfn, section_nr;
+
+ start_pfn = PFN_DOWN(start);
+ end_pfn = start_pfn + PFN_DOWN(start);
+
+ 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;
+ if (mem->state == MEM_OFFLINE)
+ continue;
+
+ kobject_put(&mem->dev.kobj);
+ return false;
+ }
+
+ if (mem)
+ kobject_put(&mem->dev.kobj);
+
+ return true;
+}
+EXPORT_SYMBOL(is_memblk_offline);
+
/*
* register_memory - Setup a sysfs device for a memory block
*/
Index: linux-3.5-rc6/include/linux/memory.h
===================================================================
--- linux-3.5-rc6.orig/include/linux/memory.h 2012-07-17 11:18:00.693477455 +0900
+++ linux-3.5-rc6/include/linux/memory.h 2012-07-17 11:20:54.632302919 +0900
@@ -106,6 +106,10 @@ static inline int memory_isolate_notify(
{
return 0;
}
+static inline bool is_memblk_offline(unsigned long start, unsigned long size)
+{
+ return false;
+}
#else
extern int register_memory_notifier(struct notifier_block *nb);
extern void unregister_memory_notifier(struct notifier_block *nb);
@@ -120,6 +124,7 @@ extern int memory_isolate_notify(unsigne
extern struct memory_block *find_memory_block_hinted(struct mem_section *,
struct memory_block *);
extern struct memory_block *find_memory_block(struct mem_section *);
+extern bool is_memblk_offline(unsigned long start, unsigned long size);
#define CONFIG_MEM_BLOCK_SIZE (PAGES_PER_SECTION<<PAGE_SHIFT)
enum mem_add_context { BOOT, HOTPLUG };
#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
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