When memory is onlined, we are only able to rezone from ZONE_MOVABLE to ZONE_KERNEL, or from (ZONE_MOVABLE - 1) to ZONE_MOVABLE.
To be more flexible, use the following criteria instead; to online memory from zone X into zone Y, * Any zones between X and Y must be unused. * If X is lower than Y, the onlined memory must lie at the end of X. * If X is higher than Y, the onlined memory must lie at the start of X. Add zone_can_shift() to make this determination. Signed-off-by: Reza Arbab <[email protected]> --- include/linux/memory_hotplug.h | 2 ++ mm/memory_hotplug.c | 42 +++++++++++++++++++++++++++++++++++------- 2 files changed, 37 insertions(+), 7 deletions(-) diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index adbef58..7bff0f9 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -284,5 +284,7 @@ extern void sparse_remove_one_section(struct zone *zone, struct mem_section *ms, unsigned long map_offset); extern struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum); +extern int zone_can_shift(unsigned long pfn, unsigned long nr_pages, + enum zone_type target); #endif /* __LINUX_MEMORY_HOTPLUG_H */ diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 6b4b005..b63cc28 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1032,6 +1032,37 @@ static void node_states_set_node(int node, struct memory_notify *arg) node_set_state(node, N_MEMORY); } +int zone_can_shift(unsigned long pfn, unsigned long nr_pages, + enum zone_type target) +{ + struct zone *zone = page_zone(pfn_to_page(pfn)); + enum zone_type idx = zone_idx(zone); + int i; + + if (idx < target) { + /* pages must be at end of current zone */ + if (pfn + nr_pages != zone_end_pfn(zone)) + return 0; + + /* no zones in use between current zone and target */ + for (i = idx + 1; i < target; i++) + if (zone_is_initialized(zone - idx + i)) + return 0; + } + + if (target < idx) { + /* pages must be at beginning of current zone */ + if (pfn != zone->zone_start_pfn) + return 0; + + /* no zones in use between current zone and target */ + for (i = target + 1; i < idx; i++) + if (zone_is_initialized(zone - idx + i)) + return 0; + } + + return target - idx; +} /* Must be protected by mem_hotplug_begin() */ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type) @@ -1057,13 +1088,10 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ !can_online_high_movable(zone)) return -EINVAL; - if (online_type == MMOP_ONLINE_KERNEL && - zone_idx(zone) == ZONE_MOVABLE) - zone_shift = -1; - - if (online_type == MMOP_ONLINE_MOVABLE && - zone_idx(zone) == ZONE_MOVABLE - 1) - zone_shift = 1; + if (online_type == MMOP_ONLINE_KERNEL) + zone_shift = zone_can_shift(pfn, nr_pages, ZONE_NORMAL); + else if (online_type == MMOP_ONLINE_MOVABLE) + zone_shift = zone_can_shift(pfn, nr_pages, ZONE_MOVABLE); zone = move_pfn_range(zone_shift, pfn, pfn + nr_pages); if (!zone) -- 1.8.3.1
