Re: [PATCH v12 05/10] drm/i915: Use huge tmpfs mountpoint helpers
From: Tvrtko Ursulin <tursulin@ursulin.net>
Date: 2025-12-05 11:18:45
Also in:
dri-devel, intel-gfx, linux-mm, lkml
On 05/12/2025 09:12, Loïc Molinari wrote:
Make use of the new drm_gem_huge_mnt_create() and drm_gem_get_huge_mnt() helpers to avoid code duplication. Now that it's just a few lines long, the single function in i915_gemfs.c is moved into i915_gem_shmem.c. v3: - use huge tmpfs mountpoint in drm_device - move i915_gemfs.c into i915_gem_shmem.c v4: - clean up mountpoint creation error handling v5: - use drm_gem_has_huge_mnt() helper v7: - include <drm/drm_print.h> in i915_gem_shmem.c v8: - keep logging notice message with CONFIG_TRANSPARENT_HUGEPAGE=n - don't access huge_mnt field with CONFIG_TRANSPARENT_HUGEPAGE=n v9: - replace drm_gem_has_huge_mnt() by drm_gem_get_huge_mnt() - remove useless ternary op test in selftests/huge_pages.c v12: - fix layering violation in selftests (Tvrtko) - fix incorrect filename in commit message
Thanks, looks good to me. Acked-by: Tvrtko Ursulin <redacted> What are your plans for landing the series? Presumably you'd like to do it in one go via drm-misc-next rather than in stages and different trees? Regards, Tvrtko
quoted hunk ↗ jump to hunk
Signed-off-by: Loïc Molinari <redacted> --- drivers/gpu/drm/i915/Makefile | 3 +- .../gpu/drm/i915/gem/i915_gem_object_types.h | 9 +-- drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 58 ++++++++++----- drivers/gpu/drm/i915/gem/i915_gemfs.c | 71 ------------------- drivers/gpu/drm/i915/gem/i915_gemfs.h | 14 ---- .../gpu/drm/i915/gem/selftests/huge_pages.c | 15 +--- drivers/gpu/drm/i915/i915_drv.h | 5 -- 7 files changed, 50 insertions(+), 125 deletions(-) delete mode 100644 drivers/gpu/drm/i915/gem/i915_gemfs.c delete mode 100644 drivers/gpu/drm/i915/gem/i915_gemfs.hdiff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile index 84ec79b64960..b5a8c0a6b747 100644 --- a/drivers/gpu/drm/i915/Makefile +++ b/drivers/gpu/drm/i915/Makefile@@ -169,8 +169,7 @@ gem-y += \ gem/i915_gem_ttm_move.o \ gem/i915_gem_ttm_pm.o \ gem/i915_gem_userptr.o \ - gem/i915_gem_wait.o \ - gem/i915_gemfs.o + gem/i915_gem_wait.o i915-y += \ $(gem-y) \ i915_active.o \diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h index 64600aa8227f..f94409e8ec4c 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h +++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h@@ -348,12 +348,13 @@ struct drm_i915_gem_object { */ #define I915_BO_ALLOC_GPU_ONLY BIT(6) #define I915_BO_ALLOC_CCS_AUX BIT(7) +#define I915_BO_ALLOC_NOTHP BIT(8) /* * Object is allowed to retain its initial data and will not be cleared on first * access if used along with I915_BO_ALLOC_USER. This is mainly to keep * preallocated framebuffer data intact while transitioning it to i915drmfb. */ -#define I915_BO_PREALLOC BIT(8) +#define I915_BO_PREALLOC BIT(9) #define I915_BO_ALLOC_FLAGS (I915_BO_ALLOC_CONTIGUOUS | \ I915_BO_ALLOC_VOLATILE | \ I915_BO_ALLOC_CPU_CLEAR | \@@ -363,9 +364,9 @@ struct drm_i915_gem_object { I915_BO_ALLOC_GPU_ONLY | \ I915_BO_ALLOC_CCS_AUX | \ I915_BO_PREALLOC) -#define I915_BO_READONLY BIT(9) -#define I915_TILING_QUIRK_BIT 10 /* unknown swizzling; do not release! */ -#define I915_BO_PROTECTED BIT(11) +#define I915_BO_READONLY BIT(10) +#define I915_TILING_QUIRK_BIT 11 /* unknown swizzling; do not release! */ +#define I915_BO_PROTECTED BIT(12) /** * @mem_flags - Mutable placement-related flags *diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c index 26dda55a07ff..6ad1d6f99363 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c@@ -9,14 +9,16 @@ #include <linux/uio.h> #include <drm/drm_cache.h> +#include <drm/drm_gem.h> +#include <drm/drm_print.h> #include "gem/i915_gem_region.h" #include "i915_drv.h" #include "i915_gem_object.h" #include "i915_gem_tiling.h" -#include "i915_gemfs.h" #include "i915_scatterlist.h" #include "i915_trace.h" +#include "i915_utils.h" /* * Move folios to appropriate lru and release the batch, decrementing the@@ -494,9 +496,11 @@ const struct drm_i915_gem_object_ops i915_gem_shmem_ops = { static int __create_shmem(struct drm_i915_private *i915, struct drm_gem_object *obj, - resource_size_t size) + resource_size_t size, + unsigned int flags) { - unsigned long flags = VM_NORESERVE; + unsigned long shmem_flags = VM_NORESERVE; + struct vfsmount *huge_mnt; struct file *filp; drm_gem_private_object_init(&i915->drm, obj, size);@@ -515,11 +519,12 @@ static int __create_shmem(struct drm_i915_private *i915, if (BITS_PER_LONG == 64 && size > MAX_LFS_FILESIZE) return -E2BIG; - if (i915->mm.gemfs) - filp = shmem_file_setup_with_mnt(i915->mm.gemfs, "i915", size, - flags); + huge_mnt = drm_gem_get_huge_mnt(&i915->drm); + if (!(flags & I915_BO_ALLOC_NOTHP) && huge_mnt) + filp = shmem_file_setup_with_mnt(huge_mnt, "i915", size, + shmem_flags); else - filp = shmem_file_setup("i915", size, flags); + filp = shmem_file_setup("i915", size, shmem_flags); if (IS_ERR(filp)) return PTR_ERR(filp);@@ -548,7 +553,7 @@ static int shmem_object_init(struct intel_memory_region *mem, gfp_t mask; int ret; - ret = __create_shmem(i915, &obj->base, size); + ret = __create_shmem(i915, &obj->base, size, flags); if (ret) return ret;@@ -644,21 +649,40 @@ i915_gem_object_create_shmem_from_data(struct drm_i915_private *i915, static int init_shmem(struct intel_memory_region *mem) { - i915_gemfs_init(mem->i915); - intel_memory_region_set_name(mem, "system"); + struct drm_i915_private *i915 = mem->i915; - return 0; /* We have fallback to the kernel mnt if gemfs init failed. */ -} + /* + * By creating our own shmemfs mountpoint, we can pass in + * mount flags that better match our usecase. + * + * One example, although it is probably better with a per-file + * control, is selecting huge page allocations ("huge=within_size"). + * However, we only do so on platforms which benefit from it, or to + * offset the overhead of iommu lookups, where with latter it is a net + * win even on platforms which would otherwise see some performance + * regressions such a slow reads issue on Broadwell and Skylake. + */ -static int release_shmem(struct intel_memory_region *mem) -{ - i915_gemfs_fini(mem->i915); - return 0; + if (GRAPHICS_VER(i915) < 11 && !i915_vtd_active(i915)) + goto no_thp; + + drm_gem_huge_mnt_create(&i915->drm, "within_size"); + if (drm_gem_get_huge_mnt(&i915->drm)) + drm_info(&i915->drm, "Using Transparent Hugepages\n"); + else + drm_notice(&i915->drm, + "Transparent Hugepage support is recommended for optimal performance%s\n", + GRAPHICS_VER(i915) >= 11 ? " on this platform!" : + " when IOMMU is enabled!"); + + no_thp: + intel_memory_region_set_name(mem, "system"); + + return 0; /* We have fallback to the kernel mnt if huge mnt failed. */ } static const struct intel_memory_region_ops shmem_region_ops = { .init = init_shmem, - .release = release_shmem, .init_object = shmem_object_init, };diff --git a/drivers/gpu/drm/i915/gem/i915_gemfs.c b/drivers/gpu/drm/i915/gem/i915_gemfs.c deleted file mode 100644 index 1f1290214031..000000000000 --- a/drivers/gpu/drm/i915/gem/i915_gemfs.c +++ /dev/null@@ -1,71 +0,0 @@ -// SPDX-License-Identifier: MIT -/* - * Copyright © 2017 Intel Corporation - */ - -#include <linux/fs.h> -#include <linux/mount.h> -#include <linux/fs_context.h> - -#include <drm/drm_print.h> - -#include "i915_drv.h" -#include "i915_gemfs.h" -#include "i915_utils.h" - -void i915_gemfs_init(struct drm_i915_private *i915) -{ - struct file_system_type *type; - struct fs_context *fc; - struct vfsmount *gemfs; - int ret; - - /* - * By creating our own shmemfs mountpoint, we can pass in - * mount flags that better match our usecase. - * - * One example, although it is probably better with a per-file - * control, is selecting huge page allocations ("huge=within_size"). - * However, we only do so on platforms which benefit from it, or to - * offset the overhead of iommu lookups, where with latter it is a net - * win even on platforms which would otherwise see some performance - * regressions such a slow reads issue on Broadwell and Skylake. - */ - - if (GRAPHICS_VER(i915) < 11 && !i915_vtd_active(i915)) - return; - - if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) - goto err; - - type = get_fs_type("tmpfs"); - if (!type) - goto err; - - fc = fs_context_for_mount(type, SB_KERNMOUNT); - if (IS_ERR(fc)) - goto err; - ret = vfs_parse_fs_string(fc, "source", "tmpfs"); - if (!ret) - ret = vfs_parse_fs_string(fc, "huge", "within_size"); - if (!ret) - gemfs = fc_mount_longterm(fc); - put_fs_context(fc); - if (ret) - goto err; - - i915->mm.gemfs = gemfs; - drm_info(&i915->drm, "Using Transparent Hugepages\n"); - return; - -err: - drm_notice(&i915->drm, - "Transparent Hugepage support is recommended for optimal performance%s\n", - GRAPHICS_VER(i915) >= 11 ? " on this platform!" : - " when IOMMU is enabled!"); -} - -void i915_gemfs_fini(struct drm_i915_private *i915) -{ - kern_unmount(i915->mm.gemfs); -}diff --git a/drivers/gpu/drm/i915/gem/i915_gemfs.h b/drivers/gpu/drm/i915/gem/i915_gemfs.h deleted file mode 100644 index 16d4333c9a4e..000000000000 --- a/drivers/gpu/drm/i915/gem/i915_gemfs.h +++ /dev/null@@ -1,14 +0,0 @@ -/* SPDX-License-Identifier: MIT */ -/* - * Copyright © 2017 Intel Corporation - */ - -#ifndef __I915_GEMFS_H__ -#define __I915_GEMFS_H__ - -struct drm_i915_private; - -void i915_gemfs_init(struct drm_i915_private *i915); -void i915_gemfs_fini(struct drm_i915_private *i915); - -#endifdiff --git a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c index bd08605a1611..02e9bf87f654 100644 --- a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c +++ b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c@@ -1316,7 +1316,7 @@ typedef struct drm_i915_gem_object * static inline bool igt_can_allocate_thp(struct drm_i915_private *i915) { - return i915->mm.gemfs && has_transparent_hugepage(); + return !!drm_gem_get_huge_mnt(&i915->drm); } static struct drm_i915_gem_object *@@ -1761,7 +1761,6 @@ static int igt_tmpfs_fallback(void *arg) struct drm_i915_private *i915 = arg; struct i915_address_space *vm; struct i915_gem_context *ctx; - struct vfsmount *gemfs = i915->mm.gemfs; struct drm_i915_gem_object *obj; struct i915_vma *vma; struct file *file;@@ -1779,15 +1778,8 @@ static int igt_tmpfs_fallback(void *arg) } vm = i915_gem_context_get_eb_vm(ctx); - /* - * Make sure that we don't burst into a ball of flames upon falling back - * to tmpfs, which we rely on if on the off-chance we encounter a failure - * when setting up gemfs. - */ - - i915->mm.gemfs = NULL; - - obj = i915_gem_object_create_shmem(i915, PAGE_SIZE); + obj = i915_gem_object_create_region(i915->mm.regions[INTEL_REGION_SMEM], + PAGE_SIZE, 0, I915_BO_ALLOC_NOTHP); if (IS_ERR(obj)) { err = PTR_ERR(obj); goto out_restore;@@ -1819,7 +1811,6 @@ static int igt_tmpfs_fallback(void *arg) out_put: i915_gem_object_put(obj); out_restore: - i915->mm.gemfs = gemfs; i915_vm_put(vm); out:diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 95f9ddf22ce4..93a5af3de334 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h@@ -141,11 +141,6 @@ struct i915_gem_mm { */ atomic_t free_count; - /** - * tmpfs instance used for shmem backed objects - */ - struct vfsmount *gemfs; - struct intel_memory_region *regions[INTEL_REGION_UNKNOWN]; struct notifier_block oom_notifier;