diff mbox

[v2,1/7] memory-hotplug: add zone_for_memory() for selecting zone for new memory

Message ID 1405914402-66212-2-git-send-email-wangnan0@huawei.com
State Accepted
Commit 6326440077a48d2c3b2993f3b3f2d969f09b6917
Headers show

Commit Message

Wang Nan July 21, 2014, 3:46 a.m. UTC
This patch introduces a zone_for_memory function in arch independent
code for arch_add_memory() using.

Many arch_add_memory() function simply selects ZONE_HIGHMEM or
ZONE_NORMAL and add new memory into it. However, with the existance of
ZONE_MOVABLE, the selection method should be carefully considered: if
new, higher memory is added after ZONE_MOVABLE is setup, the default
zone and ZONE_MOVABLE may overlap each other.

should_add_memory_movable() checks the status of ZONE_MOVABLE. If it has
already contain memory, compare the address of new memory and movable
memory. If new memory is higher than movable, it should be added into
ZONE_MOVABLE instead of default zone.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Dave Hansen <dave.hansen@intel.com>
---
 include/linux/memory_hotplug.h |  1 +
 mm/memory_hotplug.c            | 28 ++++++++++++++++++++++++++++
 2 files changed, 29 insertions(+)

Comments

Sergei Shtylyov July 21, 2014, 5:19 p.m. UTC | #1
Hello.

On 07/21/2014 07:46 AM, Wang Nan wrote:

    Some grammar nitpicking.

> This patch introduces a zone_for_memory function in arch independent
> code for arch_add_memory() using.

    s/ using/'s use/.

> Many arch_add_memory() function simply selects ZONE_HIGHMEM or

    Plural needed with "many".

> ZONE_NORMAL and add new memory into it. However, with the existance of
> ZONE_MOVABLE, the selection method should be carefully considered: if
> new, higher memory is added after ZONE_MOVABLE is setup, the default
> zone and ZONE_MOVABLE may overlap each other.

> should_add_memory_movable() checks the status of ZONE_MOVABLE. If it has
> already contain memory, compare the address of new memory and movable
> memory. If new memory is higher than movable, it should be added into
> ZONE_MOVABLE instead of default zone.

> Signed-off-by: Wang Nan <wangnan0@huawei.com>
> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
> Cc: Dave Hansen <dave.hansen@intel.com>
[...]

> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 469bbf5..348fda7 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1156,6 +1156,34 @@ static int check_hotplug_memory_range(u64 start, u64 size)
>   	return 0;
>   }
>
> +/*
> + * If movable zone has already been setup, newly added memory should be check.

    Checked.

WBR, Sergei

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diff mbox

Patch

diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 010d125..3de3d02 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -258,6 +258,7 @@  static inline void remove_memory(int nid, u64 start, u64 size) {}
 extern int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,
 		void *arg, int (*func)(struct memory_block *, void *));
 extern int add_memory(int nid, u64 start, u64 size);
+extern int zone_for_memory(int nid, u64 start, u64 size, int zone_default);
 extern int arch_add_memory(int nid, u64 start, u64 size);
 extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages);
 extern bool is_memblock_offlined(struct memory_block *mem);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 469bbf5..348fda7 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1156,6 +1156,34 @@  static int check_hotplug_memory_range(u64 start, u64 size)
 	return 0;
 }
 
+/*
+ * If movable zone has already been setup, newly added memory should be check.
+ * If its address is higher than movable zone, it should be added as movable.
+ * Without this check, movable zone may overlap with other zone.
+ */
+static int should_add_memory_movable(int nid, u64 start, u64 size)
+{
+	unsigned long start_pfn = start >> PAGE_SHIFT;
+	pg_data_t *pgdat = NODE_DATA(nid);
+	struct zone *movable_zone = pgdat->node_zones + ZONE_MOVABLE;
+
+	if (zone_is_empty(movable_zone))
+		return 0;
+
+	if (movable_zone->zone_start_pfn <= start_pfn)
+		return 1;
+
+	return 0;
+}
+
+int zone_for_memory(int nid, u64 start, u64 size, int zone_default)
+{
+	if (should_add_memory_movable(nid, start, size))
+		return ZONE_MOVABLE;
+
+	return zone_default;
+}
+
 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
 int __ref add_memory(int nid, u64 start, u64 size)
 {