[PATCH v3 02/15] mm: introduce is_huge_pmd() helper

From: Qi Zheng
Date: Wed Nov 10 2021 - 05:54:57 EST


Currently we have some times the following judgments repeated in the
code:

is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) || pmd_devmap(*pmd)

which is to determine whether the *pmd is a huge pmd, so introduce
is_huge_pmd() helper to deduplicate them.

Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
---
include/linux/huge_mm.h | 10 +++++++---
mm/huge_memory.c | 3 +--
mm/memory.c | 5 ++---
mm/mprotect.c | 2 +-
mm/mremap.c | 3 +--
5 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index f280f33ff223..b37a89180846 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -199,8 +199,7 @@ void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
#define split_huge_pmd(__vma, __pmd, __address) \
do { \
pmd_t *____pmd = (__pmd); \
- if (is_swap_pmd(*____pmd) || pmd_trans_huge(*____pmd) \
- || pmd_devmap(*____pmd)) \
+ if (is_huge_pmd(*____pmd)) \
__split_huge_pmd(__vma, __pmd, __address, \
false, NULL); \
} while (0)
@@ -232,11 +231,16 @@ static inline int is_swap_pmd(pmd_t pmd)
return !pmd_none(pmd) && !pmd_present(pmd);
}

+static inline int is_huge_pmd(pmd_t pmd)
+{
+ return is_swap_pmd(pmd) || pmd_trans_huge(pmd) || pmd_devmap(pmd);
+}
+
/* mmap_lock must be held on entry */
static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
struct vm_area_struct *vma)
{
- if (is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) || pmd_devmap(*pmd))
+ if (is_huge_pmd(*pmd))
return __pmd_trans_huge_lock(pmd, vma);
else
return NULL;
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index e5483347291c..e76ee2e1e423 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1832,8 +1832,7 @@ spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma)
{
spinlock_t *ptl;
ptl = pmd_lock(vma->vm_mm, pmd);
- if (likely(is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) ||
- pmd_devmap(*pmd)))
+ if (likely(is_huge_pmd(*pmd)))
return ptl;
spin_unlock(ptl);
return NULL;
diff --git a/mm/memory.c b/mm/memory.c
index 855486fff526..b00cd60fc368 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1146,8 +1146,7 @@ copy_pmd_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma,
src_pmd = pmd_offset(src_pud, addr);
do {
next = pmd_addr_end(addr, end);
- if (is_swap_pmd(*src_pmd) || pmd_trans_huge(*src_pmd)
- || pmd_devmap(*src_pmd)) {
+ if (is_huge_pmd(*src_pmd)) {
int err;
VM_BUG_ON_VMA(next-addr != HPAGE_PMD_SIZE, src_vma);
err = copy_huge_pmd(dst_mm, src_mm, dst_pmd, src_pmd,
@@ -1441,7 +1440,7 @@ static inline unsigned long zap_pmd_range(struct mmu_gather *tlb,
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
- if (is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) || pmd_devmap(*pmd)) {
+ if (is_huge_pmd(*pmd)) {
if (next - addr != HPAGE_PMD_SIZE)
__split_huge_pmd(vma, pmd, addr, false, NULL);
else if (zap_huge_pmd(tlb, vma, pmd, addr))
diff --git a/mm/mprotect.c b/mm/mprotect.c
index e552f5e0ccbd..2d5064a4631c 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -257,7 +257,7 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
mmu_notifier_invalidate_range_start(&range);
}

- if (is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) || pmd_devmap(*pmd)) {
+ if (is_huge_pmd(*pmd)) {
if (next - addr != HPAGE_PMD_SIZE) {
__split_huge_pmd(vma, pmd, addr, false, NULL);
} else {
diff --git a/mm/mremap.c b/mm/mremap.c
index 002eec83e91e..c6e9da09dd0a 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -532,8 +532,7 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
new_pmd = alloc_new_pmd(vma->vm_mm, vma, new_addr);
if (!new_pmd)
break;
- if (is_swap_pmd(*old_pmd) || pmd_trans_huge(*old_pmd) ||
- pmd_devmap(*old_pmd)) {
+ if (is_huge_pmd(*old_pmd)) {
if (extent == HPAGE_PMD_SIZE &&
move_pgt_entry(HPAGE_PMD, vma, old_addr, new_addr,
old_pmd, new_pmd, need_rmap_locks))
--
2.11.0