Adds an option on kernel config to make hot-added memory online in ZONE_MOVABLE by default. This would be great in systems with MEMORY_HOTPLUG_DEFAULT_ONLINE=y by allowing to choose which zone it will be auto-onlined Signed-off-by: Leonardo Bras <leonardo@xxxxxxxxxxxxx> --- drivers/base/memory.c | 3 +++ mm/Kconfig | 14 ++++++++++++++ 2 files changed, 17 insertions(+) diff --git a/drivers/base/memory.c b/drivers/base/memory.c index f180427e48f4..378b585785c1 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -670,6 +670,9 @@ static int init_memory_block(struct memory_block **memory, mem->state = state; start_pfn = section_nr_to_pfn(mem->start_section_nr); mem->phys_device = arch_get_memory_phys_device(start_pfn); +#ifdef CONFIG_MEMORY_HOTPLUG_MOVABLE + mem->online_type = MMOP_ONLINE_MOVABLE; +#endif ret = register_memory(mem); diff --git a/mm/Kconfig b/mm/Kconfig index f0c76ba47695..74e793720f43 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -180,6 +180,20 @@ config MEMORY_HOTREMOVE depends on MEMORY_HOTPLUG && ARCH_ENABLE_MEMORY_HOTREMOVE depends on MIGRATION +config MEMORY_HOTPLUG_MOVABLE + bool "Enhance the likelihood of hot-remove" + depends on MEMORY_HOTREMOVE + help + This option sets the hot-added memory zone to MOVABLE which + drastically reduces the chance of a hot-remove to fail due to + unmovable memory segments. Kernel memory can't be allocated in + this zone. + + Say Y here if you want to have better chance to hot-remove memory + that have been previously hot-added. + Say N here if you want to make all hot-added memory available to + kernel space. + # Heavily threaded applications may benefit from splitting the mm-wide # page_table_lock, so that faults on different parts of the user address # space can be handled with less contention: split it at this NR_CPUS. -- 2.20.1
