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mm,hugetlb: make unmap_ref_private() return void 

This function always returns 1, thus no need to check return value in
hugetlb_cow().  By doing so, we can get rid of the unnecessary WARN_ON
call.  While this logic perhaps existed as a way of identifying future
unmap_ref_private() mishandling, reality is it serves no apparent
purpose.

Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Davidlohr Bueso 2014-08-06 16:06:45 -07:00 committed by Linus Torvalds
parent eb39d618f9
commit 2f4612af43
1 changed files with 14 additions and 18 deletions
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32
mm/hugetlb.c
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@ -2754,8 +2754,8 @@ void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
* from other VMAs and let the children be SIGKILLed if they are faulting the
* same region.
*/
static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
struct page *page, unsigned long address)
static void unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
struct page *page, unsigned long address)
{
struct hstate *h = hstate_vma(vma);
struct vm_area_struct *iter_vma;
@ -2794,8 +2794,6 @@ static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
address + huge_page_size(h), page);
}
mutex_unlock(&mapping->i_mmap_mutex);
return 1;
}
/*
@ -2857,20 +2855,18 @@ retry_avoidcopy:
*/
if (outside_reserve) {
BUG_ON(huge_pte_none(pte));
if (unmap_ref_private(mm, vma, old_page, address)) {
BUG_ON(huge_pte_none(pte));
spin_lock(ptl);
ptep = huge_pte_offset(mm, address & huge_page_mask(h));
if (likely(ptep &&
pte_same(huge_ptep_get(ptep), pte)))
goto retry_avoidcopy;
/*
* race occurs while re-acquiring page table
* lock, and our job is done.
*/
return 0;
}
WARN_ON_ONCE(1);
unmap_ref_private(mm, vma, old_page, address);
BUG_ON(huge_pte_none(pte));
spin_lock(ptl);
ptep = huge_pte_offset(mm, address & huge_page_mask(h));
if (likely(ptep &&
pte_same(huge_ptep_get(ptep), pte)))
goto retry_avoidcopy;
/*
* race occurs while re-acquiring page table
* lock, and our job is done.
*/
return 0;
}
/* Caller expects lock to be held */