diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/Kconfig | 17 | ||||
| -rw-r--r-- | mm/memory_hotplug.c | 14 | ||||
| -rw-r--r-- | mm/page_alloc.c | 3 |
3 files changed, 31 insertions, 3 deletions
diff --git a/mm/Kconfig b/mm/Kconfig index d4e6495a720f..3a4070f5ab79 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -648,3 +648,20 @@ config DEFERRED_STRUCT_PAGE_INIT when kswapd starts. This has a potential performance impact on processes running early in the lifetime of the systemm until kswapd finishes the initialisation. + +config ZONE_DEVICE + bool "Device memory (pmem, etc...) hotplug support" if EXPERT + default !ZONE_DMA + depends on !ZONE_DMA + depends on MEMORY_HOTPLUG + depends on MEMORY_HOTREMOVE + depends on X86_64 #arch_add_memory() comprehends device memory + + help + Device memory hotplug support allows for establishing pmem, + or other device driver discovered memory regions, in the + memmap. This allows pfn_to_page() lookups of otherwise + "device-physical" addresses which is needed for using a DAX + mapping in an O_DIRECT operation, among other things. + + If FS_DAX is enabled, then say Y. diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 8fd97dac538a..aa992e2df58a 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -778,7 +778,10 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, start = phys_start_pfn << PAGE_SHIFT; size = nr_pages * PAGE_SIZE; - ret = release_mem_region_adjustable(&iomem_resource, start, size); + + /* in the ZONE_DEVICE case device driver owns the memory region */ + if (!is_dev_zone(zone)) + ret = release_mem_region_adjustable(&iomem_resource, start, size); if (ret) { resource_size_t endres = start + size - 1; @@ -1215,8 +1218,13 @@ static int should_add_memory_movable(int nid, u64 start, u64 size) return 0; } -int zone_for_memory(int nid, u64 start, u64 size, int zone_default) +int zone_for_memory(int nid, u64 start, u64 size, int zone_default, + bool for_device) { +#ifdef CONFIG_ZONE_DEVICE + if (for_device) + return ZONE_DEVICE; +#endif if (should_add_memory_movable(nid, start, size)) return ZONE_MOVABLE; @@ -1265,7 +1273,7 @@ int __ref add_memory(int nid, u64 start, u64 size) } /* call arch's memory hotadd */ - ret = arch_add_memory(nid, start, size); + ret = arch_add_memory(nid, start, size, false); if (ret < 0) goto error; diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 5b5240b7f642..b401d40cb4fd 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -206,6 +206,9 @@ static char * const zone_names[MAX_NR_ZONES] = { "HighMem", #endif "Movable", +#ifdef CONFIG_ZONE_DEVICE + "Device", +#endif }; int min_free_kbytes = 1024; |