The patch titled
Subject: mm: introduce pmd_install() helper
has been added to the -mm tree. Its filename is
mm-introduce-pmd_install-helper.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-introduce-pmd_install-helper.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-introduce-pmd_install-helper.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Subject: mm: introduce pmd_install() helper
Patch series "Do some code cleanups related to mm", v3.
This patch (of 2):
Currently we have three times the same few lines repeated in the code.
Deduplicate them by newly introduced pmd_install() helper.
Link: https://lkml.kernel.org/r/20210901102722.47686-1-zhengqi.arch@xxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/20210901102722.47686-2-zhengqi.arch@xxxxxxxxxxxxx
Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
Cc: Mika Penttila <mika.penttila@xxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/filemap.c | 11 ++---------
mm/internal.h | 1 +
mm/memory.c | 34 ++++++++++++++++------------------
3 files changed, 19 insertions(+), 27 deletions(-)
--- a/mm/filemap.c~mm-introduce-pmd_install-helper
+++ a/mm/filemap.c
@@ -3210,15 +3210,8 @@ static bool filemap_map_pmd(struct vm_fa
}
}
- if (pmd_none(*vmf->pmd)) {
- vmf->ptl = pmd_lock(mm, vmf->pmd);
- if (likely(pmd_none(*vmf->pmd))) {
- mm_inc_nr_ptes(mm);
- pmd_populate(mm, vmf->pmd, vmf->prealloc_pte);
- vmf->prealloc_pte = NULL;
- }
- spin_unlock(vmf->ptl);
- }
+ if (pmd_none(*vmf->pmd))
+ pmd_install(mm, vmf->pmd, &vmf->prealloc_pte);
/* See comment in handle_pte_fault() */
if (pmd_devmap_trans_unstable(vmf->pmd)) {
--- a/mm/internal.h~mm-introduce-pmd_install-helper
+++ a/mm/internal.h
@@ -38,6 +38,7 @@ vm_fault_t do_swap_page(struct vm_fault
void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
unsigned long floor, unsigned long ceiling);
+void pmd_install(struct mm_struct *mm, pmd_t *pmd, pgtable_t *pte);
static inline bool can_madv_lru_vma(struct vm_area_struct *vma)
{
--- a/mm/memory.c~mm-introduce-pmd_install-helper
+++ a/mm/memory.c
@@ -433,9 +433,20 @@ void free_pgtables(struct mmu_gather *tl
}
}
+void pmd_install(struct mm_struct *mm, pmd_t *pmd, pgtable_t *pte)
+{
+ spinlock_t *ptl = pmd_lock(mm, pmd);
+
+ if (likely(pmd_none(*pmd))) { /* Has another populated it ? */
+ mm_inc_nr_ptes(mm);
+ pmd_populate(mm, pmd, *pte);
+ *pte = NULL;
+ }
+ spin_unlock(ptl);
+}
+
int __pte_alloc(struct mm_struct *mm, pmd_t *pmd)
{
- spinlock_t *ptl;
pgtable_t new = pte_alloc_one(mm);
if (!new)
return -ENOMEM;
@@ -455,13 +466,7 @@ int __pte_alloc(struct mm_struct *mm, pm
*/
smp_wmb(); /* Could be smp_wmb__xxx(before|after)_spin_lock */
- ptl = pmd_lock(mm, pmd);
- if (likely(pmd_none(*pmd))) { /* Has another populated it ? */
- mm_inc_nr_ptes(mm);
- pmd_populate(mm, pmd, new);
- new = NULL;
- }
- spin_unlock(ptl);
+ pmd_install(mm, pmd, &new);
if (new)
pte_free(mm, new);
return 0;
@@ -4014,17 +4019,10 @@ vm_fault_t finish_fault(struct vm_fault
return ret;
}
- if (vmf->prealloc_pte) {
- vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd);
- if (likely(pmd_none(*vmf->pmd))) {
- mm_inc_nr_ptes(vma->vm_mm);
- pmd_populate(vma->vm_mm, vmf->pmd, vmf->prealloc_pte);
- vmf->prealloc_pte = NULL;
- }
- spin_unlock(vmf->ptl);
- } else if (unlikely(pte_alloc(vma->vm_mm, vmf->pmd))) {
+ if (vmf->prealloc_pte)
+ pmd_install(vma->vm_mm, vmf->pmd, &vmf->prealloc_pte);
+ else if (unlikely(pte_alloc(vma->vm_mm, vmf->pmd)))
return VM_FAULT_OOM;
- }
}
/* See comment in handle_pte_fault() */
_
Patches currently in -mm which might be from zhengqi.arch@xxxxxxxxxxxxx are
mm-introduce-pmd_install-helper.patch
mm-remove-redundant-smp_wmb.patch
