From: "Thomas Hellstrom (VMware)" thomas_os@shipmail.org

With amdgpu and CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS=y, there are errors like: BUG: non-zero pgtables_bytes on freeing mm and: BUG: Bad rss-counter state with TTM transparent huge-pages. Until we've figured out what other TTM drivers do differently compared to vmwgfx, disable the huge_fault() callback, eliminating transhuge page-table entries.

Cc: Christian König christian.koenig@amd.com Signed-off-by: Thomas Hellstrom (VMware) thomas_os@shipmail.org Reported-by: Alex Xu (Hello71) alex_y_xu@yahoo.ca Tested-by: Alex Xu (Hello71) alex_y_xu@yahoo.ca --- drivers/gpu/drm/ttm/ttm_bo_vm.c | 63 --------------------------------- 1 file changed, 63 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c index 6ee3b96f0d13..0ad30b112982 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -442,66 +442,6 @@ vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) } EXPORT_SYMBOL(ttm_bo_vm_fault);

-#ifdef CONFIG_TRANSPARENT_HUGEPAGE -/** - * ttm_pgprot_is_wrprotecting - Is a page protection value write-protecting? - * @prot: The page protection value - * - * Return: true if @prot is write-protecting. false otherwise. - */ -static bool ttm_pgprot_is_wrprotecting(pgprot_t prot) -{ - /* - * This is meant to say "pgprot_wrprotect(prot) == prot" in a generic - * way. Unfortunately there is no generic pgprot_wrprotect. - */ - return pte_val(pte_wrprotect(__pte(pgprot_val(prot)))) == - pgprot_val(prot); -} - -static vm_fault_t ttm_bo_vm_huge_fault(struct vm_fault *vmf, - enum page_entry_size pe_size) -{ - struct vm_area_struct *vma = vmf->vma; - pgprot_t prot; - struct ttm_buffer_object *bo = vma->vm_private_data; - vm_fault_t ret; - pgoff_t fault_page_size = 0; - bool write = vmf->flags & FAULT_FLAG_WRITE; - - switch (pe_size) { - case PE_SIZE_PMD: - fault_page_size = HPAGE_PMD_SIZE >> PAGE_SHIFT; - break; -#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD - case PE_SIZE_PUD: - fault_page_size = HPAGE_PUD_SIZE >> PAGE_SHIFT; - break; -#endif - default: - WARN_ON_ONCE(1); - return VM_FAULT_FALLBACK; - } - - /* Fallback on write dirty-tracking or COW */ - if (write && ttm_pgprot_is_wrprotecting(vma->vm_page_prot)) - return VM_FAULT_FALLBACK; - - ret = ttm_bo_vm_reserve(bo, vmf); - if (ret) - return ret; - - prot = vm_get_page_prot(vma->vm_flags); - ret = ttm_bo_vm_fault_reserved(vmf, prot, 1, fault_page_size); - if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) - return ret; - - dma_resv_unlock(bo->base.resv); - - return ret; -} -#endif - void ttm_bo_vm_open(struct vm_area_struct *vma) { struct ttm_buffer_object *bo = vma->vm_private_data; @@ -604,9 +544,6 @@ static const struct vm_operations_struct ttm_bo_vm_ops = { .open = ttm_bo_vm_open, .close = ttm_bo_vm_close, .access = ttm_bo_vm_access, -#ifdef CONFIG_TRANSPARENT_HUGEPAGE - .huge_fault = ttm_bo_vm_huge_fault, -#endif };

static struct ttm_buffer_object *ttm_bo_vm_lookup(struct ttm_bo_device *bdev,