Messages in this thread Patch in this message | | | Date | Thu, 08 Mar 2012 17:59:02 +0800 | From | Xiao Guangrong <> | Subject | Re: linux-next: manual merge of the akpm tree with Linus' tree |
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On 03/08/2012 03:50 PM, Andrew Morton wrote:
> Doh. The author reviewed that for me too! > > I'll drop it - please rework, retest and resend? >
Andrew, the patch has been reworked.
Subject: [PATCH] hugetlb: drop prev_vma in hugetlb_get_unmapped_area_topdown()
After the call find_vma_prev(mm, addr, &prev_vma), the following condition is always true:
!prev_vma || (addr >= prev_vma->vm_end)
it can happily drop prev_vma and use find_vma() instead of find_vma_prev().
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> --- arch/x86/mm/hugetlbpage.c | 18 +++++------------- 1 files changed, 5 insertions(+), 13 deletions(-)
diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c index 8ecbb4b..0c1701b 100644 --- a/arch/x86/mm/hugetlbpage.c +++ b/arch/x86/mm/hugetlbpage.c @@ -308,7 +308,7 @@ static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file, { struct hstate *h = hstate_file(file); struct mm_struct *mm = current->mm; - struct vm_area_struct *vma, *prev_vma; + struct vm_area_struct *vma; unsigned long base = mm->mmap_base, addr = addr0; unsigned long largest_hole = mm->cached_hole_size; int first_time = 1; @@ -337,22 +337,14 @@ try_again: if (!vma) return addr;
- /* - * new region fits between prev_vma->vm_end and - * vma->vm_start, use it: - */ - prev_vma = vma->vm_prev; - if (addr + len <= vma->vm_start && - (!prev_vma || (addr >= prev_vma->vm_end))) { + if (addr + len <= vma->vm_start) { /* remember the address as a hint for next time */ mm->cached_hole_size = largest_hole; return (mm->free_area_cache = addr); - } else { + } else if (mm->free_area_cache == vma->vm_end) { /* pull free_area_cache down to the first hole */ - if (mm->free_area_cache == vma->vm_end) { - mm->free_area_cache = vma->vm_start; - mm->cached_hole_size = largest_hole; - } + mm->free_area_cache = vma->vm_start; + mm->cached_hole_size = largest_hole; }
/* remember the largest hole we saw so far */ -- 1.7.7.6
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