diff options
Diffstat (limited to 'Documentation/driver-api/cxl/allocation/hugepages.rst')
| -rw-r--r-- | Documentation/driver-api/cxl/allocation/hugepages.rst | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/Documentation/driver-api/cxl/allocation/hugepages.rst b/Documentation/driver-api/cxl/allocation/hugepages.rst new file mode 100644 index 000000000000..1023c6922829 --- /dev/null +++ b/Documentation/driver-api/cxl/allocation/hugepages.rst @@ -0,0 +1,32 @@ +.. SPDX-License-Identifier: GPL-2.0 + +========== +Huge Pages +========== + +Contiguous Memory Allocator +=========================== +CXL Memory onlined as SystemRAM during early boot is eligible for use by CMA, +as the NUMA node hosting that capacity will be `Online` at the time CMA +carves out contiguous capacity. + +CXL Memory deferred to the CXL Driver for configuration cannot have its +capacity allocated by CMA - as the NUMA node hosting the capacity is `Offline` +at :code:`__init` time - when CMA carves out contiguous capacity. + +HugeTLB +======= +Different huge page sizes allow different memory configurations. + +2MB Huge Pages +-------------- +All CXL capacity regardless of configuration time or memory zone is eligible +for use as 2MB huge pages. + +1GB Huge Pages +-------------- +CXL capacity onlined in :code:`ZONE_NORMAL` is eligible for 1GB Gigantic Page +allocation. + +CXL capacity onlined in :code:`ZONE_MOVABLE` is not eligible for 1GB Gigantic +Page allocation. |