[RFC] : ACPI: Automatically online hot-added memory

Commit Message

Prarit Bhargava March 9, 2010, 2:12 p.m. UTC

None

Patch

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 93d2c79..dece6bd 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -350,6 +350,14 @@  config ACPI_HOTPLUG_MEMORY
 	  To compile this driver as a module, choose M here:
 	  the module will be called acpi_memhotplug.
 
+config ACPI_HOTPLUG_MEMORY_AUTO_ONLINE
+	bool "Automatically online hotplugged memory"
+	depends on ACPI_HOTPLUG_MEMORY
+	default n
+	help
+	  This forces memory that is brought into service by ACPI
+	  to be automatically onlined.
+
 config ACPI_SBS
 	tristate "Smart Battery System"
 	depends on X86
diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index 3597d73..9814c50 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -30,6 +30,7 @@ 
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/memory_hotplug.h>
+#include <linux/memory.h>
 #include <acpi/acpi_drivers.h>
 
 #define ACPI_MEMORY_DEVICE_CLASS		"memory"
@@ -252,6 +253,19 @@  static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 		result = add_memory(node, info->start_addr, info->length);
 		if (result)
 			continue;
+#ifdef CONFIG_ACPI_HOTPLUG_MEMORY_AUTO_ONLINE
+		/*
+		 * New processors require memory to be online before cpus.
+		 * No notifications are required here as "we" are the only
+		 * ones who know about the new memory right now.
+		 */
+		result = online_pages(info->start_addr >> PAGE_SHIFT,
+				      info->length >> PAGE_SHIFT);
+		if (!result)
+			set_memory_state(info->start_addr, MEM_ONLINE);
+		else
+			printk("Memory online failed.\n");
+#endif
 		info->enabled = 1;
 		num_enabled++;
 	}
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 2f86915..fb465d5 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -510,6 +510,20 @@  int remove_memory_block(unsigned long node_id, struct mem_section *section,
 }
 
 /*
+ * need an interface for the VM to mark sections on and offline when hot-adding
+ * memory.
+ */
+void set_memory_state(unsigned long addr, unsigned long state)
+{
+	struct mem_section *section;
+	struct memory_block *mem;
+
+	section = __pfn_to_section(addr >> PAGE_SHIFT);
+	mem = find_memory_block(section);
+	mem->state = state;
+}
+
+/*
  * need an interface for the VM to add new memory regions,
  * but without onlining it.
  */
diff --git a/include/linux/memory.h b/include/linux/memory.h
index 1adfe77..5d8d78c 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -112,6 +112,7 @@  extern int remove_memory_block(unsigned long, struct mem_section *, int);
 extern int memory_notify(unsigned long val, void *v);
 extern int memory_isolate_notify(unsigned long val, void *v);
 extern struct memory_block *find_memory_block(struct mem_section *);
+extern void set_memory_state(unsigned long, unsigned long);
 #define CONFIG_MEM_BLOCK_SIZE	(PAGES_PER_SECTION<<PAGE_SHIFT)
 enum mem_add_context { BOOT, HOTPLUG };
 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */