>
> From: Changsheng Liu <liuchangcheng@xxxxxxxxxx>
>
> After the user config CONFIG_MOVABLE_NODE,
> When the memory is hot added, should_add_memory_movable() return 0
> because all zones including movable zone are empty,
> so the memory that was hot added will be added to the normal zone
> and the normal zone will be created firstly.
> But we want the whole node to be added to movable zone defaultly.
>
> So we change should_add_memory_movable(): if the user config
> CONFIG_MOVABLE_NODE and sysctl parameter hotadd_memory_as_movable and
> the ZONE_NORMAL is empty or the pfn of the hot-added memory
> is after the end of the ZONE_NORMAL it will always return 1
> and all zones is empty at the same time,
> so that the movable zone will be created firstly
> and then the whole node will be added to movable zone defaultly.
> If we want the node to be added to normal zone,
> we can do it as follows:
> "echo online_kernel > /sys/devices/system/memory/memoryXXX/state"
>
> Signed-off-by: Changsheng Liu <liuchangsheng@xxxxxxxxxx>
> Signed-off-by: Xiaofeng Yan <yanxiaofeng@xxxxxxxxxx>
> Tested-by: Dongdong Fan <fandd@xxxxxxxxxx>
> Cc: Wang Nan <wangnan0@xxxxxxxxxx>
> Cc: Zhang Yanfei <zhangyanfei@xxxxxxxxxxxxxx>
> Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
> Cc: Yinghai Lu <yinghai@xxxxxxxxxx>
> Cc: Tang Chen <tangchen@xxxxxxxxxxxxxx>
> Cc: Hu Tao <hutao@xxxxxxxxxxxxxx>
> Cc: Lai Jiangshan <laijs@xxxxxxxxxxxxxx>
> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
> Cc: Gu Zheng <guz.fnst@xxxxxxxxxxxxxx>
> Cc: Toshi Kani <toshi.kani@xxxxxx>
> Cc: Xishi Qiu <qiuxishi@xxxxxxxxxx>
> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Hm... by AKPM, Advanced kernel Programming Master, really?
> ---
> Documentation/memory-hotplug.txt | 5 ++++-
> kernel/sysctl.c | 15 +++++++++++++++
> mm/memory_hotplug.c | 23 +++++++++++++++++++++++
> 3 files changed, 42 insertions(+), 1 deletions(-)
>
> diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt
> index ce2cfcf..7e6b4f4 100644
> --- a/Documentation/memory-hotplug.txt
> +++ b/Documentation/memory-hotplug.txt
> @@ -277,7 +277,7 @@ And if the memory block is in ZONE_MOVABLE, you can change it to ZONE_NORMAL:
> After this, memory block XXX's state will be 'online' and the amount of
> available memory will be increased.
>
> -Currently, newly added memory is added as ZONE_NORMAL (for powerpc, ZONE_DMA).
> +Currently, newly added memory is added as ZONE_NORMAL or ZONE_MOVABLE (for powerpc, ZONE_DMA).
> This may be changed in future.
>
>
> @@ -319,6 +319,9 @@ creates ZONE_MOVABLE as following.
> Size of memory not for movable pages (not for offline) is TOTAL - ZZZZ.
> Size of memory for movable pages (for offline) is ZZZZ.
>
> +And a sysctl parameter for assigning the hot added memory to ZONE_MOVABLE is
> +supported. If the value of "kernel/hotadd_memory_as_movable" is 1,the hot added
> +memory will be assigned to ZONE_MOVABLE defautly.
>
> Note: Unfortunately, there is no information to show which memory block belongs
> to ZONE_MOVABLE. This is TBD.
> diff --git a/kernel/sysctl.c b/kernel/sysctl.c
> index 19b62b5..855c48e 100644
> --- a/kernel/sysctl.c
> +++ b/kernel/sysctl.c
> @@ -166,6 +166,10 @@ extern int unaligned_dump_stack;
> extern int no_unaligned_warning;
> #endif
>
> +#ifdef CONFIG_MOVABLE_NODE
> +extern int hotadd_memory_as_movable;
> +#endif
> +
> #ifdef CONFIG_PROC_SYSCTL
>
> #define SYSCTL_WRITES_LEGACY -1
> @@ -1139,6 +1143,17 @@ static struct ctl_table kern_table[] = {
> .proc_handler = timer_migration_handler,
> },
> #endif
> +/*If the value of "kernel/hotadd_memory_as_movable" is 1,the hot added
> + * memory will be assigned to ZONE_MOVABLE defautly.*/
> +#ifdef CONFIG_MOVABLE_NODE
> + {
> + .procname = "hotadd_memory_as_movable",
> + .data = &hotadd_memory_as_movable,
> + .maxlen = sizeof(int),
> + .mode = 0644,
> + .proc_handler = proc_dointvec,
> + },
> +#endif
> { }
> };
>
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 26fbba7..5bcaf74 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -37,6 +37,10 @@
>
> #include "internal.h"
>
> +/*If the global variable value is 1,
> + * the hot added memory will be assigned to ZONE_MOVABLE defautly*/
> +int hotadd_memory_as_movable;
> +
> /*
> * online_page_callback contains pointer to current page onlining function.
> * Initially it is generic_online_page(). If it is required it could be
> @@ -1190,6 +1194,9 @@ static int check_hotplug_memory_range(u64 start, u64 size)
> /*
> * 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.
> + * And if system config CONFIG_MOVABLE_NODE and set the sysctl parameter
> + * "hotadd_memory_as_movable" and added memory does not overlap the zone
> + * before MOVABLE_ZONE,the memory is 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)
> @@ -1197,6 +1204,22 @@ 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;
> + struct zone *pre_zone = pgdat->node_zones + (ZONE_MOVABLE - 1);
> + /*
> + * The system configs CONFIG_MOVABLE_NODE to assign a node
> + * which has only movable memory,so the hot-added memory should
> + * be assigned to ZONE_MOVABLE defaultly,
> + * but the function zone_for_memory() assign the hot-added memory
> + * to ZONE_NORMAL(x86_64) defaultly.Kernel does not allow to
> + * create ZONE_MOVABLE before ZONE_NORMAL,so If the value of
> + * sysctl parameter "hotadd_memory_as_movable" is 1
> + * and the ZONE_NORMAL is empty or the pfn of the hot-added memory
> + * is after the end of the ZONE_NORMAL
> + * the hot-added memory will be assigned to ZONE_MOVABLE.
> + */
> + if (hotadd_memory_as_movable
> + && (zone_is_empty(pre_zone) || zone_end_pfn(pre_zone) <= start_pfn))
> + return 1;
>
> if (zone_is_empty(movable_zone))
> return 0;
> --
> 1.7.1
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>