From b5df09226450165c434084d346fcb6d4858b0d52 Mon Sep 17 00:00:00 2001 From: "Liam R. Howlett" Date: Mon, 24 Jul 2023 14:31:52 -0400 Subject: mm: set up vma iterator for vma_iter_prealloc() calls Set the correct limits for vma_iter_prealloc() calls so that the maple tree can be smarter about how many nodes are needed. Link: https://lkml.kernel.org/r/20230724183157.3939892-11-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett Cc: Peng Zhang Cc: Suren Baghdasaryan Signed-off-by: Andrew Morton --- mm/mmap.c | 69 ++++++++++++++++++++++++++++++++++++++------------------------- 1 file changed, 42 insertions(+), 27 deletions(-) (limited to 'mm/mmap.c') diff --git a/mm/mmap.c b/mm/mmap.c index 1ddb024995df..3f10e708ba72 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -397,7 +397,8 @@ static int vma_link(struct mm_struct *mm, struct vm_area_struct *vma) VMA_ITERATOR(vmi, mm, 0); struct address_space *mapping = NULL; - if (vma_iter_prealloc(&vmi)) + vma_iter_config(&vmi, vma->vm_start, vma->vm_end); + if (vma_iter_prealloc(&vmi, vma)) return -ENOMEM; vma_iter_store(&vmi, vma); @@ -649,19 +650,16 @@ int vma_expand(struct vma_iterator *vmi, struct vm_area_struct *vma, /* Only handles expanding */ VM_WARN_ON(vma->vm_start < start || vma->vm_end > end); - if (vma_iter_prealloc(vmi)) + /* Note: vma iterator must be pointing to 'start' */ + vma_iter_config(vmi, start, end); + if (vma_iter_prealloc(vmi, vma)) goto nomem; vma_prepare(&vp); vma_adjust_trans_huge(vma, start, end, 0); - /* VMA iterator points to previous, so set to start if necessary */ - if (vma_iter_addr(vmi) != start) - vma_iter_set(vmi, start); - vma->vm_start = start; vma->vm_end = end; vma->vm_pgoff = pgoff; - /* Note: mas must be pointing to the expanding VMA */ vma_iter_store(vmi, vma); vma_complete(&vp, vmi, vma->vm_mm); @@ -687,19 +685,19 @@ int vma_shrink(struct vma_iterator *vmi, struct vm_area_struct *vma, WARN_ON((vma->vm_start != start) && (vma->vm_end != end)); - if (vma_iter_prealloc(vmi)) + if (vma->vm_start < start) + vma_iter_config(vmi, vma->vm_start, start); + else + vma_iter_config(vmi, end, vma->vm_end); + + if (vma_iter_prealloc(vmi, NULL)) return -ENOMEM; init_vma_prep(&vp, vma); vma_prepare(&vp); vma_adjust_trans_huge(vma, start, end, 0); - if (vma->vm_start < start) - vma_iter_clear(vmi, vma->vm_start, start); - - if (vma->vm_end > end) - vma_iter_clear(vmi, end, vma->vm_end); - + vma_iter_clear(vmi); vma->vm_start = start; vma->vm_end = end; vma->vm_pgoff = pgoff; @@ -973,7 +971,17 @@ struct vm_area_struct *vma_merge(struct vma_iterator *vmi, struct mm_struct *mm, if (err) return NULL; - if (vma_iter_prealloc(vmi)) + if (vma_start < vma->vm_start || vma_end > vma->vm_end) + vma_expanded = true; + + if (vma_expanded) { + vma_iter_config(vmi, vma_start, vma_end); + } else { + vma_iter_config(vmi, adjust->vm_start + adj_start, + adjust->vm_end); + } + + if (vma_iter_prealloc(vmi, vma)) return NULL; init_multi_vma_prep(&vp, vma, adjust, remove, remove2); @@ -982,8 +990,6 @@ struct vm_area_struct *vma_merge(struct vma_iterator *vmi, struct mm_struct *mm, vma_prepare(&vp); vma_adjust_trans_huge(vma, vma_start, vma_end, adj_start); - if (vma_start < vma->vm_start || vma_end > vma->vm_end) - vma_expanded = true; vma->vm_start = vma_start; vma->vm_end = vma_end; @@ -1923,7 +1929,7 @@ static int expand_upwards(struct vm_area_struct *vma, unsigned long address) struct vm_area_struct *next; unsigned long gap_addr; int error = 0; - MA_STATE(mas, &mm->mm_mt, 0, 0); + MA_STATE(mas, &mm->mm_mt, vma->vm_start, address); if (!(vma->vm_flags & VM_GROWSUP)) return -EFAULT; @@ -1948,6 +1954,10 @@ static int expand_upwards(struct vm_area_struct *vma, unsigned long address) /* Check that both stack segments have the same anon_vma? */ } + if (next) + mas_prev_range(&mas, address); + + __mas_set_range(&mas, vma->vm_start, address - 1); if (mas_preallocate(&mas, vma, GFP_KERNEL)) return -ENOMEM; @@ -1993,7 +2003,6 @@ static int expand_upwards(struct vm_area_struct *vma, unsigned long address) anon_vma_interval_tree_pre_update_vma(vma); vma->vm_end = address; /* Overwrite old entry in mtree. */ - mas_set_range(&mas, vma->vm_start, address - 1); mas_store_prealloc(&mas, vma); anon_vma_interval_tree_post_update_vma(vma); spin_unlock(&mm->page_table_lock); @@ -2038,6 +2047,10 @@ int expand_downwards(struct vm_area_struct *vma, unsigned long address) return -ENOMEM; } + if (prev) + mas_next_range(&mas, vma->vm_start); + + __mas_set_range(&mas, address, vma->vm_end - 1); if (mas_preallocate(&mas, vma, GFP_KERNEL)) return -ENOMEM; @@ -2084,7 +2097,6 @@ int expand_downwards(struct vm_area_struct *vma, unsigned long address) vma->vm_start = address; vma->vm_pgoff -= grow; /* Overwrite old entry in mtree. */ - mas_set_range(&mas, address, vma->vm_end - 1); mas_store_prealloc(&mas, vma); anon_vma_interval_tree_post_update_vma(vma); spin_unlock(&mm->page_table_lock); @@ -2325,10 +2337,6 @@ int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma, if (!new) return -ENOMEM; - err = -ENOMEM; - if (vma_iter_prealloc(vmi)) - goto out_free_vma; - if (new_below) { new->vm_end = addr; } else { @@ -2336,6 +2344,11 @@ int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma, new->vm_pgoff += ((addr - vma->vm_start) >> PAGE_SHIFT); } + err = -ENOMEM; + vma_iter_config(vmi, new->vm_start, new->vm_end); + if (vma_iter_prealloc(vmi, new)) + goto out_free_vma; + err = vma_dup_policy(vma, new); if (err) goto out_free_vmi; @@ -2693,7 +2706,6 @@ unsigned long mmap_region(struct file *file, unsigned long addr, vma_iter_next_range(&vmi); } - /* Actually expand, if possible */ if (vma && !vma_expand(&vmi, vma, merge_start, merge_end, vm_pgoff, next)) { @@ -2790,7 +2802,7 @@ cannot_expand: goto close_and_free_vma; error = -ENOMEM; - if (vma_iter_prealloc(&vmi)) + if (vma_iter_prealloc(&vmi, vma)) goto close_and_free_vma; /* Lock the VMA since it is modified after insertion into VMA tree */ @@ -3053,7 +3065,8 @@ static int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *vma, if (vma && vma->vm_end == addr && !vma_policy(vma) && can_vma_merge_after(vma, flags, NULL, NULL, addr >> PAGE_SHIFT, NULL_VM_UFFD_CTX, NULL)) { - if (vma_iter_prealloc(vmi)) + vma_iter_config(vmi, vma->vm_start, addr + len); + if (vma_iter_prealloc(vmi, vma)) goto unacct_fail; init_vma_prep(&vp, vma); @@ -3068,6 +3081,8 @@ static int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *vma, goto out; } + if (vma) + vma_iter_next_range(vmi); /* create a vma struct for an anonymous mapping */ vma = vm_area_alloc(mm); if (!vma) -- cgit