[PATCH 04/10] mm: Add a pmd_fault handler
From: Matthew Wilcox <hidden>
Date: 2015-07-10 20:29:19
Also in:
linux-fsdevel, lkml
Subsystem:
memory management, memory management - core, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
From: Matthew Wilcox <redacted> Allow non-anonymous VMAs to provide huge pages in response to a page fault. Signed-off-by: Matthew Wilcox <redacted> --- include/linux/mm.h | 2 ++ mm/memory.c | 30 ++++++++++++++++++++++++------ 2 files changed, 26 insertions(+), 6 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 2e872f9..00473e4 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h@@ -246,6 +246,8 @@ struct vm_operations_struct { void (*open)(struct vm_area_struct * area); void (*close)(struct vm_area_struct * area); int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf); + int (*pmd_fault)(struct vm_area_struct *, unsigned long address, + pmd_t *, unsigned int flags); void (*map_pages)(struct vm_area_struct *vma, struct vm_fault *vmf); /* notification that a previously read-only page is about to become
diff --git a/mm/memory.c b/mm/memory.c
index a84fbb7..32007d6 100644
--- a/mm/memory.c
+++ b/mm/memory.c@@ -3209,6 +3209,27 @@ out: return 0; } +static int create_huge_pmd(struct mm_struct *mm, struct vm_area_struct *vma, + unsigned long address, pmd_t *pmd, unsigned int flags) +{ + if (!vma->vm_ops) + return do_huge_pmd_anonymous_page(mm, vma, address, pmd, flags); + if (vma->vm_ops->pmd_fault) + return vma->vm_ops->pmd_fault(vma, address, pmd, flags); + return VM_FAULT_FALLBACK; +} + +static int wp_huge_pmd(struct mm_struct *mm, struct vm_area_struct *vma, + unsigned long address, pmd_t *pmd, pmd_t orig_pmd, + unsigned int flags) +{ + if (!vma->vm_ops) + return do_huge_pmd_wp_page(mm, vma, address, pmd, orig_pmd); + if (vma->vm_ops->pmd_fault) + return vma->vm_ops->pmd_fault(vma, address, pmd, flags); + return VM_FAULT_FALLBACK; +} + /* * These routines also need to handle stuff like marking pages dirty * and/or accessed for architectures that don't do it in hardware (most
@@ -3312,10 +3333,7 @@ static int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, if (!pmd) return VM_FAULT_OOM; if (pmd_none(*pmd) && transparent_hugepage_enabled(vma)) { - int ret = VM_FAULT_FALLBACK; - if (!vma->vm_ops) - ret = do_huge_pmd_anonymous_page(mm, vma, address, - pmd, flags); + int ret = create_huge_pmd(mm, vma, address, pmd, flags); if (!(ret & VM_FAULT_FALLBACK)) return ret; } else {
@@ -3339,8 +3357,8 @@ static int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, orig_pmd, pmd); if (dirty && !pmd_write(orig_pmd)) { - ret = do_huge_pmd_wp_page(mm, vma, address, pmd, - orig_pmd); + ret = wp_huge_pmd(mm, vma, address, pmd, + orig_pmd, flags); if (!(ret & VM_FAULT_FALLBACK)) return ret; } else {
--
2.1.4
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