diff options
| -rw-r--r-- | Documentation/memory-hotplug.txt | 12 | ||||
| -rw-r--r-- | mm/memory_hotplug.c | 19 |
2 files changed, 25 insertions, 6 deletions
diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt index 670f3ded0802..5c628e19d6cd 100644 --- a/Documentation/memory-hotplug.txt +++ b/Documentation/memory-hotplug.txt @@ -282,20 +282,26 @@ offlined it is possible to change the individual block's state by writing to the % echo online > /sys/devices/system/memory/memoryXXX/state This onlining will not change the ZONE type of the target memory block, -If the memory block is in ZONE_NORMAL, you can change it to ZONE_MOVABLE: +If the memory block doesn't belong to any zone an appropriate kernel zone +(usually ZONE_NORMAL) will be used unless movable_node kernel command line +option is specified when ZONE_MOVABLE will be used. + +You can explicitly request to associate it with ZONE_MOVABLE by % echo online_movable > /sys/devices/system/memory/memoryXXX/state (NOTE: current limit: this memory block must be adjacent to ZONE_MOVABLE) -And if the memory block is in ZONE_MOVABLE, you can change it to ZONE_NORMAL: +Or you can explicitly request a kernel zone (usually ZONE_NORMAL) by: % echo online_kernel > /sys/devices/system/memory/memoryXXX/state (NOTE: current limit: this memory block must be adjacent to ZONE_NORMAL) +An explicit zone onlining can fail (e.g. when the range is already within +and existing and incompatible zone already). + 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). This may be changed in future. diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 7b1311ac5f7b..32abde2e2472 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -934,6 +934,19 @@ struct zone *default_zone_for_pfn(int nid, unsigned long start_pfn, return &pgdat->node_zones[ZONE_NORMAL]; } +static inline bool movable_pfn_range(int nid, struct zone *default_zone, + unsigned long start_pfn, unsigned long nr_pages) +{ + if (!allow_online_pfn_range(nid, start_pfn, nr_pages, + MMOP_ONLINE_KERNEL)) + return true; + + if (!movable_node_is_enabled()) + return false; + + return !zone_intersects(default_zone, start_pfn, nr_pages); +} + /* * Associates the given pfn range with the given node and the zone appropriate * for the given online type. @@ -949,10 +962,10 @@ static struct zone * __meminit move_pfn_range(int online_type, int nid, /* * MMOP_ONLINE_KEEP defaults to MMOP_ONLINE_KERNEL but use * movable zone if that is not possible (e.g. we are within - * or past the existing movable zone) + * or past the existing movable zone). movable_node overrides + * this default and defaults to movable zone */ - if (!allow_online_pfn_range(nid, start_pfn, nr_pages, - MMOP_ONLINE_KERNEL)) + if (movable_pfn_range(nid, zone, start_pfn, nr_pages)) zone = movable_zone; } else if (online_type == MMOP_ONLINE_MOVABLE) { zone = &pgdat->node_zones[ZONE_MOVABLE]; |