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@xxxxxxxxxxxxxxx>
---
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 21fda6a10e89..ba655d4d6864 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 0eda67376df4..2d91438cf14a 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4673,7 +4673,8 @@ 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);
@@ -4861,7 +4862,8 @@ 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;
--
2.7.0.rc3
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