[PATCH v4 64/66] nommu: Remove uses of VMA linked list
From: Liam Howlett <hidden>
Date: 2021-12-01 14:34:33
Also in:
lkml
Subsystem:
memory management, memory mapping, the rest · Maintainers:
Andrew Morton, Liam R. Howlett, Lorenzo Stoakes, Linus Torvalds
From: "Matthew Wilcox (Oracle)" <willy@infradead.org> Use the maple tree or VMA iterator instead. This is faster and will allow us to shrink the VMA. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Liam R. Howlett <redacted> --- mm/nommu.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/mm/nommu.c b/mm/nommu.c
index 11ae550834cd..acb9aafb0afc 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c@@ -1370,6 +1370,7 @@ static int shrink_vma(struct mm_struct *mm, */ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list_head *uf) { + MA_STATE(mas, &mm->mm_mt, start, start); struct vm_area_struct *vma; unsigned long end; int ret;
@@ -1381,7 +1382,7 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list end = start + len; /* find the first potentially overlapping VMA */ - vma = find_vma(mm, start); + vma = mas_find(&mas, end - 1); if (!vma) { static int limit; if (limit < 5) {
@@ -1400,7 +1401,7 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list return -EINVAL; if (end == vma->vm_end) goto erase_whole_vma; - vma = vma->vm_next; + vma = mas_next(&mas, end - 1); } while (vma); return -EINVAL; } else {
@@ -1449,6 +1450,7 @@ SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len) */ void exit_mmap(struct mm_struct *mm) { + VMA_ITERATOR(vmi, mm, 0); struct vm_area_struct *vma; if (!mm)
@@ -1456,12 +1458,14 @@ void exit_mmap(struct mm_struct *mm) mm->total_vm = 0; - while ((vma = mm->mmap)) { - mm->mmap = vma->vm_next; + mmap_write_lock(mm); + for_each_vma(vmi, vma) { delete_vma_from_mm(vma); delete_vma(mm, vma); cond_resched(); } + __mt_destroy(&mm->mm_mt); + mmap_write_unlock(mm); } int vm_brk(unsigned long addr, unsigned long len)
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2.30.2