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| author | Kirill A. Shutemov | 2016-01-22 01:40:25 +0100 |
|---|---|---|
| committer | Linus Torvalds | 2016-01-22 02:20:51 +0100 |
| commit | b6ec57f4b92e9bae4617f7d98a054d45370284bb (patch) | |
| tree | 31b894dc2fa7c8a885baa4be7094c73002999719 /mm/huge_memory.c | |
| parent | Merge branch 'uaccess' (batched user access infrastructure) (diff) | |
| download | kernel-qcow2-linux-b6ec57f4b92e9bae4617f7d98a054d45370284bb.tar.gz kernel-qcow2-linux-b6ec57f4b92e9bae4617f7d98a054d45370284bb.tar.xz kernel-qcow2-linux-b6ec57f4b92e9bae4617f7d98a054d45370284bb.zip | |
thp: change pmd_trans_huge_lock() interface to return ptl
After THP refcounting rework we have only two possible return values
from pmd_trans_huge_lock(): success and failure. Return-by-pointer for
ptl doesn't make much sense in this case.
Let's convert pmd_trans_huge_lock() to return ptl on success and NULL on
failure.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Minchan Kim <minchan@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/huge_memory.c')
| -rw-r--r-- | mm/huge_memory.c | 24 |
1 files changed, 14 insertions, 10 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 8ad580273521..2d1ffe9d0e26 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1560,7 +1560,8 @@ int madvise_free_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, struct mm_struct *mm = tlb->mm; int ret = 0; - if (!pmd_trans_huge_lock(pmd, vma, &ptl)) + ptl = pmd_trans_huge_lock(pmd, vma); + if (!ptl) goto out_unlocked; orig_pmd = *pmd; @@ -1627,7 +1628,8 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, pmd_t orig_pmd; spinlock_t *ptl; - if (!__pmd_trans_huge_lock(pmd, vma, &ptl)) + ptl = __pmd_trans_huge_lock(pmd, vma); + if (!ptl) return 0; /* * For architectures like ppc64 we look at deposited pgtable @@ -1690,7 +1692,8 @@ bool move_huge_pmd(struct vm_area_struct *vma, struct vm_area_struct *new_vma, * We don't have to worry about the ordering of src and dst * ptlocks because exclusive mmap_sem prevents deadlock. */ - if (__pmd_trans_huge_lock(old_pmd, vma, &old_ptl)) { + old_ptl = __pmd_trans_huge_lock(old_pmd, vma); + if (old_ptl) { new_ptl = pmd_lockptr(mm, new_pmd); if (new_ptl != old_ptl) spin_lock_nested(new_ptl, SINGLE_DEPTH_NESTING); @@ -1724,7 +1727,8 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, spinlock_t *ptl; int ret = 0; - if (__pmd_trans_huge_lock(pmd, vma, &ptl)) { + ptl = __pmd_trans_huge_lock(pmd, vma); + if (ptl) { pmd_t entry; bool preserve_write = prot_numa && pmd_write(*pmd); ret = 1; @@ -1760,14 +1764,14 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, * Note that if it returns true, this routine returns without unlocking page * table lock. So callers must unlock it. */ -bool __pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma, - spinlock_t **ptl) +spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma) { - *ptl = pmd_lock(vma->vm_mm, pmd); + spinlock_t *ptl; + ptl = pmd_lock(vma->vm_mm, pmd); if (likely(pmd_trans_huge(*pmd) || pmd_devmap(*pmd))) - return true; - spin_unlock(*ptl); - return false; + return ptl; + spin_unlock(ptl); + return NULL; } #define VM_NO_THP (VM_SPECIAL | VM_HUGETLB | VM_SHARED | VM_MAYSHARE) |