This series aims to reduce the page tables overhead of DRM drivers for builds with CONFIG_TRANSPARENT_HUGEPAGE enabled and either the sysfs knob '/sys/kernel/mm/transparent_hugepage/shmem_enabled' appropriately set or drivers using a dedicated huge tmpfs mount point.
It starts by implementing a map_pages handler for GEM objects to map pages around a faulty address in a single batch. It also checks in both the fault and fault-around handlers whether a faulty address is part of a huge page in order to attempt a PMD sized PFN insertion into the VMA. It then introduces a dedicated get_unmapped_area file operation on the DRM file descriptor for GEM objects to get the best virtual address alignment for the underlying shmem buffers. The remaining commits propose shmem helpers to create and release huge tmpfs mount points and adapt the i915 and V3D drivers. The helpers are then used to optionally enable Transparent Hugepage for Panfrost and Panthor. For Panthor on a Rock 5B, this series makes the first memcpy() to an entire BO object mapped in userspace about twice as fast with Transparent Hugepage enabled. Note that some architectures like arm64 with the contiguous page hint (contptes) would very likely benefit from a vmf_insert_pfns() function based on set_ptes() to insert a range of contiguous ptes. Loïc Molinari (12): drm/shmem-helper: Simplify page offset calculation in fault handler drm/shmem-helper: Implement map_pages fault-around handler drm/shmem-helper: Map huge pages in fault handlers drm/gem: Introduce drm_gem_get_unmapped_area() fop drm/gem: Add huge tmpfs mountpoint helpers drm/i915: Use huge tmpfs mountpoint helpers drm/v3d: Use huge tmpfs mountpoint helpers drm/gem: Get rid of *_with_mnt helpers drm/panthor: Introduce huge tmpfs mountpoint option drm/panthor: Improve IOMMU map/unmap debugging logs drm/panfrost: Introduce huge tmpfs mountpoint option Documentation/gpu/drm-mm: Add THP paragraph to GEM mapping section Documentation/gpu/drm-mm.rst | 25 ++- drivers/gpu/drm/drm_gem.c | 184 +++++++++++++----- drivers/gpu/drm/drm_gem_shmem_helper.c | 142 ++++++++++---- drivers/gpu/drm/i915/Makefile | 3 +- drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 47 +++-- drivers/gpu/drm/i915/gem/i915_gemfs.c | 69 ------- drivers/gpu/drm/i915/gem/i915_gemfs.h | 14 -- .../gpu/drm/i915/gem/selftests/huge_pages.c | 11 +- drivers/gpu/drm/i915/i915_drv.h | 5 - drivers/gpu/drm/panfrost/panfrost_device.c | 3 + drivers/gpu/drm/panfrost/panfrost_drv.c | 6 + drivers/gpu/drm/panfrost/panfrost_drv.h | 9 + drivers/gpu/drm/panfrost/panfrost_gem.c | 18 ++ drivers/gpu/drm/panfrost/panfrost_gem.h | 2 + drivers/gpu/drm/panthor/panthor_device.c | 3 + drivers/gpu/drm/panthor/panthor_drv.c | 7 + drivers/gpu/drm/panthor/panthor_drv.h | 9 + drivers/gpu/drm/panthor/panthor_gem.c | 18 ++ drivers/gpu/drm/panthor/panthor_gem.h | 2 + drivers/gpu/drm/panthor/panthor_mmu.c | 19 +- drivers/gpu/drm/v3d/Makefile | 3 +- drivers/gpu/drm/v3d/v3d_bo.c | 6 +- drivers/gpu/drm/v3d/v3d_drv.c | 2 +- drivers/gpu/drm/v3d/v3d_drv.h | 11 +- drivers/gpu/drm/v3d/v3d_gem.c | 27 ++- drivers/gpu/drm/v3d/v3d_gemfs.c | 60 ------ include/drm/drm_device.h | 15 ++ include/drm/drm_gem.h | 59 +++++- include/drm/drm_gem_shmem_helper.h | 3 - mm/shmem.c | 1 + 30 files changed, 491 insertions(+), 292 deletions(-) delete mode 100644 drivers/gpu/drm/i915/gem/i915_gemfs.c delete mode 100644 drivers/gpu/drm/i915/gem/i915_gemfs.h create mode 100644 drivers/gpu/drm/panfrost/panfrost_drv.h create mode 100644 drivers/gpu/drm/panthor/panthor_drv.h delete mode 100644 drivers/gpu/drm/v3d/v3d_gemfs.c -- 2.47.3
