From b3b9c2932c32e0692018ed5f12f3fd8c70eea8ce Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Mon, 8 Oct 2012 16:28:34 -0700 Subject: mm, x86, pat: rework linear pfn-mmap tracking Replace the generic vma-flag VM_PFN_AT_MMAP with x86-only VM_PAT. We can toss mapping address from remap_pfn_range() into track_pfn_vma_new(), and collect all PAT-related logic together in arch/x86/. This patch also restores orignal frustration-free is_cow_mapping() check in remap_pfn_range(), as it was before commit v2.6.28-rc8-88-g3c8bb73 ("x86: PAT: store vm_pgoff for all linear_over_vma_region mappings - v3") is_linear_pfn_mapping() checks can be removed from mm/huge_memory.c, because it already handled by VM_PFNMAP in VM_NO_THP bit-mask. [suresh.b.siddha@intel.com: Reset the VM_PAT flag as part of untrack_pfn_vma()] Signed-off-by: Konstantin Khlebnikov Signed-off-by: Suresh Siddha Cc: Venkatesh Pallipadi Cc: H. Peter Anvin Cc: Nick Piggin Cc: Ingo Molnar Cc: Alexander Viro Cc: Carsten Otte Cc: Chris Metcalf Cc: Cyrill Gorcunov Cc: Eric Paris Cc: Hugh Dickins Cc: James Morris Cc: Jason Baron Cc: Kentaro Takeda Cc: Matt Helsley Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Robert Richter Cc: Tetsuo Handa Cc: Venkatesh Pallipadi Acked-by: Linus Torvalds Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory.c | 26 ++++++++++---------------- 1 file changed, 10 insertions(+), 16 deletions(-) (limited to 'mm/memory.c') diff --git a/mm/memory.c b/mm/memory.c index 6bef278ad303..655e1429388a 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1055,7 +1055,7 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, if (is_vm_hugetlb_page(vma)) return copy_hugetlb_page_range(dst_mm, src_mm, vma); - if (unlikely(is_pfn_mapping(vma))) { + if (unlikely(vma->vm_flags & VM_PFNMAP)) { /* * We do not free on error cases below as remove_vma * gets called on error from higher level routine @@ -1327,7 +1327,7 @@ static void unmap_single_vma(struct mmu_gather *tlb, if (vma->vm_file) uprobe_munmap(vma, start, end); - if (unlikely(is_pfn_mapping(vma))) + if (unlikely(vma->vm_flags & VM_PFNMAP)) untrack_pfn(vma, 0, 0); if (start != end) { @@ -2299,26 +2299,20 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, * There's a horrible special case to handle copy-on-write * behaviour that some programs depend on. We mark the "original" * un-COW'ed pages by matching them up with "vma->vm_pgoff". + * See vm_normal_page() for details. */ - if (addr == vma->vm_start && end == vma->vm_end) { + if (is_cow_mapping(vma->vm_flags)) { + if (addr != vma->vm_start || end != vma->vm_end) + return -EINVAL; vma->vm_pgoff = pfn; - vma->vm_flags |= VM_PFN_AT_MMAP; - } else if (is_cow_mapping(vma->vm_flags)) + } + + err = track_pfn_remap(vma, &prot, pfn, addr, PAGE_ALIGN(size)); + if (err) return -EINVAL; vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP; - err = track_pfn_remap(vma, &prot, pfn, PAGE_ALIGN(size)); - if (err) { - /* - * To indicate that track_pfn related cleanup is not - * needed from higher level routine calling unmap_vmas - */ - vma->vm_flags &= ~(VM_IO | VM_RESERVED | VM_PFNMAP); - vma->vm_flags &= ~VM_PFN_AT_MMAP; - return -EINVAL; - } - BUG_ON(addr >= end); pfn -= addr >> PAGE_SHIFT; pgd = pgd_offset(mm, addr); -- cgit v1.2.3