From: Xiao Guangrong Date: Wed, 21 Mar 2012 23:34:14 +0000 (-0700) Subject: hugetlb: remove prev_vma from hugetlb_get_unmapped_area_topdown() X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=b69add218d32450d6604bc9080f6e33e19b06f5e;p=openwrt%2Fstaging%2Fblogic.git hugetlb: remove prev_vma from hugetlb_get_unmapped_area_topdown() After looking up the vma which covers or follows the cached search address, the following condition is always true: !prev_vma || (addr >= prev_vma->vm_end) so we can stop checking the previous VMA altogether. Signed-off-by: Xiao Guangrong Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c index c20e81c3425d..f6679a7fb8ca 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; unsigned long addr = addr0; unsigned long largest_hole = mm->cached_hole_size; @@ -340,22 +340,14 @@ 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 */