After the user config CONFIG_MOVABLE_NODE,
When the memory is hot added, should_add_memory_movable() return 0
because all zones including ZONE_MOVABLE are empty,
so the memory that was hot added will be assigned to ZONE_NORMAL,
and we need using the udev rules to online the memory automatically:
SUBSYSTEM=="memory", ACTION=="add", ATTR{state}=="offline",
ATTR{state}="online_movable"
The memory block onlined by udev must be adjacent to ZONE_MOVABLE.
The events of memory section are notified to udev asynchronously,
so it can not ensure that the memory block onlined by udev is
adjacent to ZONE_MOVABLE.So it can't ensure memory online always success.
But we want the whole node to be added to ZONE_MOVABLE by default.So we change should_add_memory_movable(): if the user config CONFIG_MOVABLE_NODE and movable_node kernel option 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 then the whole node will be added to ZONE_MOVABLE by default. If we want the node to be assigned to ZONE_NORMAL, we can do it as follows: "echo online_kernel > /sys/devices/system/memory/memoryXXX/state" Signed-off-by: liuchangsheng <[email protected]> Signed-off-by: Xiaofeng Yan <[email protected]> Tested-by: Dongdong Fan <[email protected]> Reviewed-by: <[email protected]> Cc: Wang Nan <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Yinghai Lu <[email protected]> Cc: Tang Chen <[email protected]> Cc: Yasuaki Ishimatsu <[email protected]> Cc: Toshi Kani <[email protected]> Cc: Xishi Qiu <[email protected]> --- mm/memory_hotplug.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index aa992e2..8617b9f 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1201,6 +1201,9 @@ 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 boots up with movable_node and config CONFIG_MOVABLE_NOD 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) @@ -1208,6 +1211,10 @@ 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); + + if (movable_node_is_enabled() && (zone_end_pfn(pre_zone) <= start_pfn)) + return 1; if (zone_is_empty(movable_zone)) return 0; -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
