[PATCH v4 09/66] mm/mmap: Use the maple tree in find_vma() instead of the rbtree.
From: Liam Howlett <hidden>
Date: 2021-12-01 14:35:20
Also in:
lkml
Subsystem:
memory management, memory mapping, the rest · Maintainers:
Andrew Morton, Liam R. Howlett, Lorenzo Stoakes, Linus Torvalds
From: "Liam R. Howlett" <redacted> Using the maple tree interface mt_find() will handle the RCU locking and will start searching at the address up to the limit, ULONG_MAX in this case. Add kernel documentation to this API. Signed-off-by: Liam R. Howlett <redacted> --- mm/mmap.c | 27 +++++++++------------------ 1 file changed, 9 insertions(+), 18 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index de78fc0ce809..6a7502f74190 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c@@ -2429,10 +2429,16 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, EXPORT_SYMBOL(get_unmapped_area); -/* Look up the first VMA which satisfies addr < vm_end, NULL if none. */ +/** + * find_vma() - Find the VMA for a given address, or the next vma. + * @mm: The mm_struct to check + * @addr: The address + * + * Returns: The VMA associated with addr, or the next vma. + * May return %NULL in the case of no vma at addr or above. + */ struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) { - struct rb_node *rb_node; struct vm_area_struct *vma; mmap_assert_locked(mm);
@@ -2441,22 +2447,7 @@ struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) if (likely(vma)) return vma; - rb_node = mm->mm_rb.rb_node; - - while (rb_node) { - struct vm_area_struct *tmp; - - tmp = rb_entry(rb_node, struct vm_area_struct, vm_rb); - - if (tmp->vm_end > addr) { - vma = tmp; - if (tmp->vm_start <= addr) - break; - rb_node = rb_node->rb_left; - } else - rb_node = rb_node->rb_right; - } - + vma = mt_find(&mm->mm_mt, &addr, ULONG_MAX); if (vma) vmacache_update(addr, vma); return vma;
--
2.30.2