Add support for Specific Purpose Memory (SPM) NUMA nodes. A SPM node is managed by the page allocator, but can only allocated by using the __GFP_SP_NODE flag with an appropriate nodemask.
Check/Set the node type (SysRAM vs SPM) at hotplug time. Disallow SPM from being added to SysRAM nodes and vice-versa. This prevents normal allocation paths (page faults, kmalloc, etc) from being directly exposed to these memories, and provides a clear integration point for buddy-allocation of SPM memory. Signed-off-by: Gregory Price <[email protected]> --- include/linux/memory_hotplug.h | 10 ++++++++++ mm/memory_hotplug.c | 7 +++++++ 2 files changed, 17 insertions(+) diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 23f038a16231..a50c467951ba 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -74,6 +74,16 @@ typedef int __bitwise mhp_t; * helpful in low-memory situations. */ #define MHP_OFFLINE_INACCESSIBLE ((__force mhp_t)BIT(3)) +/* + * The hotplugged memory can only be added to a "Specific Purpose Memory" + * NUMA node. SPM Nodes are not generally accessible by the page allocator + * by way of userland configuration - as most nodemask interfaces + * (mempolicy, cpusets) restrict nodes to SysRAM nodes. + * + * Hotplugging SPM into a SysRAM Node results in -EINVAL. + * Hotplugging SysRAM into a SPM Node results in -EINVAL. + */ +#define MHP_SPM_NODE ((__force mhp_t)BIT(4)) /* * Extended parameters for memory hotplug: diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 0be83039c3b5..488cdd8e5f6f 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -20,6 +20,7 @@ #include <linux/memory.h> #include <linux/memremap.h> #include <linux/memory_hotplug.h> +#include <linux/memory-tiers.h> #include <linux/vmalloc.h> #include <linux/ioport.h> #include <linux/delay.h> @@ -1529,6 +1530,12 @@ int add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) mem_hotplug_begin(); + /* Set the NUMA node type and bail out if the type is wrong */ + ret = mt_set_node_type(nid, (mhp_flags & MHP_SPM_NODE) ? + MT_NODE_TYPE_SPM : MT_NODE_TYPE_SYSRAM); + if (ret) + goto error_mem_hotplug_end; + if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { if (res->flags & IORESOURCE_SYSRAM_DRIVER_MANAGED) memblock_flags = MEMBLOCK_DRIVER_MANAGED; -- 2.51.1
