From b6ec57f4b92e9bae4617f7d98a054d45370284bb Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Thu, 21 Jan 2016 16:40:25 -0800 Subject: [PATCH] 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 Suggested-by: Linus Torvalds Cc: Minchan Kim Acked-by: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/task_mmu.c | 12 ++++++++---- include/linux/huge_mm.h | 16 ++++++++-------- mm/huge_memory.c | 24 ++++++++++++++---------- mm/memcontrol.c | 6 ++++-- mm/mincore.c | 3 ++- 5 files changed, 36 insertions(+), 25 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 71ffc91060f6..85d16c67c33e 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -602,7 +602,8 @@ static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, pte_t *pte; spinlock_t *ptl; - if (pmd_trans_huge_lock(pmd, vma, &ptl)) { + ptl = pmd_trans_huge_lock(pmd, vma); + if (ptl) { smaps_pmd_entry(pmd, addr, walk); spin_unlock(ptl); return 0; @@ -913,7 +914,8 @@ static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr, spinlock_t *ptl; struct page *page; - if (pmd_trans_huge_lock(pmd, vma, &ptl)) { + ptl = pmd_trans_huge_lock(pmd, vma); + if (ptl) { if (cp->type == CLEAR_REFS_SOFT_DIRTY) { clear_soft_dirty_pmd(vma, addr, pmd); goto out; @@ -1187,7 +1189,8 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end, int err = 0; #ifdef CONFIG_TRANSPARENT_HUGEPAGE - if (pmd_trans_huge_lock(pmdp, vma, &ptl)) { + ptl = pmd_trans_huge_lock(pmdp, vma); + if (ptl) { u64 flags = 0, frame = 0; pmd_t pmd = *pmdp; @@ -1519,7 +1522,8 @@ static int gather_pte_stats(pmd_t *pmd, unsigned long addr, pte_t *orig_pte; pte_t *pte; - if (pmd_trans_huge_lock(pmd, vma, &ptl)) { + ptl = pmd_trans_huge_lock(pmd, vma); + if (ptl) { pte_t huge_pte = *(pte_t *)pmd; struct page *page; diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index cfe81e10bd54..459fd25b378e 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -120,15 +120,15 @@ extern void vma_adjust_trans_huge(struct vm_area_struct *vma, unsigned long start, unsigned long end, long adjust_next); -extern bool __pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma, - spinlock_t **ptl); +extern spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd, + struct vm_area_struct *vma); /* mmap_sem must be held on entry */ -static inline bool pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma, - spinlock_t **ptl) +static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd, + struct vm_area_struct *vma) { VM_BUG_ON_VMA(!rwsem_is_locked(&vma->vm_mm->mmap_sem), vma); if (pmd_trans_huge(*pmd) || pmd_devmap(*pmd)) - return __pmd_trans_huge_lock(pmd, vma, ptl); + return __pmd_trans_huge_lock(pmd, vma); else return false; } @@ -190,10 +190,10 @@ static inline void vma_adjust_trans_huge(struct vm_area_struct *vma, long adjust_next) { } -static inline bool pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma, - spinlock_t **ptl) +static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd, + struct vm_area_struct *vma) { - return false; + return NULL; } static inline int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, 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) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index ca052f2a4a0b..d06cae2de783 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4638,7 +4638,8 @@ static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd, pte_t *pte; spinlock_t *ptl; - if (pmd_trans_huge_lock(pmd, vma, &ptl)) { + ptl = pmd_trans_huge_lock(pmd, vma); + if (ptl) { if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE) mc.precharge += HPAGE_PMD_NR; spin_unlock(ptl); @@ -4826,7 +4827,8 @@ static int mem_cgroup_move_charge_pte_range(pmd_t *pmd, union mc_target target; struct page *page; - if (pmd_trans_huge_lock(pmd, vma, &ptl)) { + ptl = pmd_trans_huge_lock(pmd, vma); + if (ptl) { if (mc.precharge < HPAGE_PMD_NR) { spin_unlock(ptl); return 0; diff --git a/mm/mincore.c b/mm/mincore.c index 2a565ed8bb49..563f32045490 100644 --- a/mm/mincore.c +++ b/mm/mincore.c @@ -117,7 +117,8 @@ static int mincore_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, unsigned char *vec = walk->private; int nr = (end - addr) >> PAGE_SHIFT; - if (pmd_trans_huge_lock(pmd, vma, &ptl)) { + ptl = pmd_trans_huge_lock(pmd, vma); + if (ptl) { memset(vec, 1, nr); spin_unlock(ptl); goto out; -- 2.30.2