Re: [RFC v9 PATCH 01/21] memory-hotplug: rename remove_memory() to offline_memory()/offline_pages()

Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx> · Fri, 28 Sep 2012 12:50:00 +0900

Hi Chen,

2012/09/28 11:22, Ni zhan Chen wrote:
On 09/05/2012 05:25 PM, wency@xxxxxxxxxxxxxx wrote:
From: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>

remove_memory() only try to offline pages. It is called in two cases:
1. hot remove a memory device
2. echo offline >/sys/devices/system/memory/memoryXX/state

In the 1st case, we should also change memory block's state, and notify
the userspace that the memory block's state is changed after offlining
pages.

So rename remove_memory() to offline_memory()/offline_pages(). And in
the 1st case, offline_memory() will be used. The function offline_memory()
is not implemented. In the 2nd case, offline_pages() will be used.

But this time there is not a function associated with add_memory.

To associate with add_memory() later, we renamed it.

Thanks,
Yasuaki Ishimatsu



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>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx>
---
  drivers/acpi/acpi_memhotplug.c |    2 +-
  drivers/base/memory.c          |    9 +++------
  include/linux/memory_hotplug.h |    3 ++-
  mm/memory_hotplug.c            |   22 ++++++++++++++--------
  4 files changed, 20 insertions(+), 16 deletions(-)

diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index 24c807f..2a7beac 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -318,7 +318,7 @@ static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
       */
      list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
          if (info->enabled) {
-            result = remove_memory(info->start_addr, info->length);
+            result = offline_memory(info->start_addr, info->length);
              if (result)
                  return result;
          }
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 7dda4f7..44e7de6 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -248,26 +248,23 @@ static bool pages_correctly_reserved(unsigned long start_pfn,
  static int
  memory_block_action(unsigned long phys_index, unsigned long action)
  {
-    unsigned long start_pfn, start_paddr;
+    unsigned long start_pfn;
      unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;
      struct page *first_page;
      int ret;
      first_page = pfn_to_page(phys_index << PFN_SECTION_SHIFT);
+    start_pfn = page_to_pfn(first_page);
      switch (action) {
          case MEM_ONLINE:
-            start_pfn = page_to_pfn(first_page);
-
              if (!pages_correctly_reserved(start_pfn, nr_pages))
                  return -EBUSY;
              ret = online_pages(start_pfn, nr_pages);
              break;
          case MEM_OFFLINE:
-            start_paddr = page_to_pfn(first_page) << PAGE_SHIFT;
-            ret = remove_memory(start_paddr,
-                        nr_pages << PAGE_SHIFT);
+            ret = offline_pages(start_pfn, nr_pages);
              break;
          default:
              WARN(1, KERN_WARNING "%s(%ld, %ld) unknown action: "
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 910550f..c183f39 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -233,7 +233,8 @@ static inline int is_mem_section_removable(unsigned long pfn,
  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 remove_memory(u64 start, u64 size);
+extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages);
+extern int offline_memory(u64 start, u64 size);
  extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
                                  int nr_pages);
  extern void sparse_remove_one_section(struct zone *zone, struct mem_section *ms);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 3ad25f9..bb42316 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -866,7 +866,7 @@ check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
      return offlined;
  }
-static int __ref offline_pages(unsigned long start_pfn,
+static int __ref __offline_pages(unsigned long start_pfn,
            unsigned long end_pfn, unsigned long timeout)
  {
      unsigned long pfn, nr_pages, expire;
@@ -994,18 +994,24 @@ out:
      return ret;
  }
-int remove_memory(u64 start, u64 size)
+int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
  {
-    unsigned long start_pfn, end_pfn;
+    return __offline_pages(start_pfn, start_pfn + nr_pages, 120 * HZ);
+}
-    start_pfn = PFN_DOWN(start);
-    end_pfn = start_pfn + PFN_DOWN(size);
-    return offline_pages(start_pfn, end_pfn, 120 * HZ);
+int offline_memory(u64 start, u64 size)
+{
+    return -EINVAL;
  }
  #else
-int remove_memory(u64 start, u64 size)
+int offline_pages(unsigned long start, unsigned long size)
+{
+    return -EINVAL;
+}
+
+int offline_memory(u64 start, u64 size)
  {
      return -EINVAL;
  }
  #endif /* CONFIG_MEMORY_HOTREMOVE */
-EXPORT_SYMBOL_GPL(remove_memory);
+EXPORT_SYMBOL_GPL(offline_memory);



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