2022-08-22 15:39:12

by Liam R. Howlett

Subject: [PATCH v13 33/70] powerpc: remove mmap linked list walks

From: "Matthew Wilcox (Oracle)" <[email protected]>

Use the VMA iterator instead.

Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Signed-off-by: Liam R. Howlett <[email protected]>
Reviewed-by: Vlastimil Babka <[email protected]>
---
arch/powerpc/kernel/vdso.c | 6 +++---
arch/powerpc/mm/book3s32/tlb.c | 11 ++++++-----
arch/powerpc/mm/book3s64/subpage_prot.c | 13 ++-----------
3 files changed, 11 insertions(+), 19 deletions(-)

diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index 0da287544054..94a8fa5017c3 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c
@@ -113,18 +113,18 @@ struct vdso_data *arch_get_vdso_data(void *vvar_page)
int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
{
struct mm_struct *mm = task->mm;
+ VMA_ITERATOR(vmi, mm, 0);
struct vm_area_struct *vma;

mmap_read_lock(mm);
-
- for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ for_each_vma(vmi, vma) {
unsigned long size = vma->vm_end - vma->vm_start;

if (vma_is_special_mapping(vma, &vvar_spec))
zap_page_range(vma, vma->vm_start, size);
}
-
mmap_read_unlock(mm);
+
return 0;
}

diff --git a/arch/powerpc/mm/book3s32/tlb.c b/arch/powerpc/mm/book3s32/tlb.c
index 19f0ef950d77..9ad6b56bfec9 100644
--- a/arch/powerpc/mm/book3s32/tlb.c
+++ b/arch/powerpc/mm/book3s32/tlb.c
@@ -81,14 +81,15 @@ EXPORT_SYMBOL(hash__flush_range);
void hash__flush_tlb_mm(struct mm_struct *mm)
{
struct vm_area_struct *mp;
+ VMA_ITERATOR(vmi, mm, 0);

/*
- * It is safe to go down the mm's list of vmas when called
- * from dup_mmap, holding mmap_lock. It would also be safe from
- * unmap_region or exit_mmap, but not from vmtruncate on SMP -
- * but it seems dup_mmap is the only SMP case which gets here.
+ * It is safe to iterate the vmas when called from dup_mmap,
+ * holding mmap_lock. It would also be safe from unmap_region
+ * or exit_mmap, but not from vmtruncate on SMP - but it seems
+ * dup_mmap is the only SMP case which gets here.
*/
- for (mp = mm->mmap; mp != NULL; mp = mp->vm_next)
+ for_each_vma(vmi, mp)
hash__flush_range(mp->vm_mm, mp->vm_start, mp->vm_end);
}
EXPORT_SYMBOL(hash__flush_tlb_mm);
diff --git a/arch/powerpc/mm/book3s64/subpage_prot.c b/arch/powerpc/mm/book3s64/subpage_prot.c
index 60c6ea16a972..d73b3b4176e8 100644
--- a/arch/powerpc/mm/book3s64/subpage_prot.c
+++ b/arch/powerpc/mm/book3s64/subpage_prot.c
@@ -149,24 +149,15 @@ static void subpage_mark_vma_nohuge(struct mm_struct *mm, unsigned long addr,
unsigned long len)
{
struct vm_area_struct *vma;
+ VMA_ITERATOR(vmi, mm, addr);

/*
* We don't try too hard, we just mark all the vma in that range
* VM_NOHUGEPAGE and split them.
*/
- vma = find_vma(mm, addr);
- /*
- * If the range is in unmapped range, just return
- */
- if (vma && ((addr + len) <= vma->vm_start))
- return;
-
- while (vma) {
- if (vma->vm_start >= (addr + len))
- break;
+ for_each_vma_range(vmi, vma, addr + len) {
vma->vm_flags |= VM_NOHUGEPAGE;
walk_page_vma(vma, &subpage_walk_ops, NULL);
- vma = vma->vm_next;
}
}
#else
--
2.35.1

2022-08-23 20:05:11

by Davidlohr Bueso

Subject: Re: [PATCH v13 33/70] powerpc: remove mmap linked list walks

On Mon, 22 Aug 2022, Liam Howlett wrote:

>From: "Matthew Wilcox (Oracle)" <[email protected]>
>
>Use the VMA iterator instead.
>
>Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
>Signed-off-by: Liam R. Howlett <[email protected]>
>Reviewed-by: Vlastimil Babka <[email protected]>

Reviewed-by: Davidlohr Bueso <[email protected]>

>---
> arch/powerpc/kernel/vdso.c | 6 +++---
> arch/powerpc/mm/book3s32/tlb.c | 11 ++++++-----
> arch/powerpc/mm/book3s64/subpage_prot.c | 13 ++-----------
> 3 files changed, 11 insertions(+), 19 deletions(-)
>
>diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
>index 0da287544054..94a8fa5017c3 100644
>--- a/arch/powerpc/kernel/vdso.c
>+++ b/arch/powerpc/kernel/vdso.c
>@@ -113,18 +113,18 @@ struct vdso_data *arch_get_vdso_data(void *vvar_page)
> int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
> {
> struct mm_struct *mm = task->mm;
>+ VMA_ITERATOR(vmi, mm, 0);
> struct vm_area_struct *vma;
>
> mmap_read_lock(mm);
>-
>- for (vma = mm->mmap; vma; vma = vma->vm_next) {
>+ for_each_vma(vmi, vma) {
> unsigned long size = vma->vm_end - vma->vm_start;

Unrelated, but maybe worth abstracting?

$> grep "vma->vm_end - vma->vm_start" |wc -l
216

Thanks,
Davidlohr