Re: [PATCH -next] Maple Tree: remove not used entry in mas_preallocate()

From: Liam Howlett
Date: Wed Aug 24 2022 - 11:04:22 EST


I'd rather not do this. I am passing this information in so that the
API can remain the same for when this information is used to make the
preallocation less greedy. Currently preallocations are done expecting
the worst-case, but with a correctly configured maple state and the
value being store, the allocation calculation can be more accurate.

* Yang Yingliang <yangyingliang@xxxxxxxxxx> [220824 04:23]:
> 'entry' is not used in mas_preallocate(), so remove it.
>
> Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
> ---
> include/linux/maple_tree.h | 2 +-
> lib/maple_tree.c | 3 +--
> lib/test_maple_tree.c | 32 ++++++++++++++++----------------
> mm/mmap.c | 14 +++++++-------
> mm/nommu.c | 8 ++++----
> 5 files changed, 29 insertions(+), 30 deletions(-)
>
> diff --git a/include/linux/maple_tree.h b/include/linux/maple_tree.h
> index a30e03b06bed..61871480d125 100644
> --- a/include/linux/maple_tree.h
> +++ b/include/linux/maple_tree.h
> @@ -456,7 +456,7 @@ int mas_store_gfp(struct ma_state *mas, void *entry, gfp_t gfp);
> void mas_store_prealloc(struct ma_state *mas, void *entry);
> void *mas_find(struct ma_state *mas, unsigned long max);
> void *mas_find_rev(struct ma_state *mas, unsigned long min);
> -int mas_preallocate(struct ma_state *mas, void *entry, gfp_t gfp);
> +int mas_preallocate(struct ma_state *mas, gfp_t gfp);
> bool mas_is_err(struct ma_state *mas);
>
> bool mas_nomem(struct ma_state *mas, gfp_t gfp);
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index e1743803c851..2adc12a83caf 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -5707,12 +5707,11 @@ void mas_store_prealloc(struct ma_state *mas, void *entry)
> /**
> * mas_preallocate() - Preallocate enough nodes for a store operation
> * @mas: The maple state
> - * @entry: The entry that will be stored
> * @gfp: The GFP_FLAGS to use for allocations.
> *
> * Return: 0 on success, -ENOMEM if memory could not be allocated.
> */
> -int mas_preallocate(struct ma_state *mas, void *entry, gfp_t gfp)
> +int mas_preallocate(struct ma_state *mas, gfp_t gfp)
> {
> int ret;
>
> diff --git a/lib/test_maple_tree.c b/lib/test_maple_tree.c
> index 4f69e009a015..80d1754de23e 100644
> --- a/lib/test_maple_tree.c
> +++ b/lib/test_maple_tree.c
> @@ -35549,7 +35549,7 @@ static noinline void check_prealloc(struct maple_tree *mt)
> for (i = 0; i <= max; i++)
> mtree_test_store_range(mt, i * 10, i * 10 + 5, &i);
>
> - MT_BUG_ON(mt, mas_preallocate(&mas, ptr, GFP_KERNEL) != 0);
> + MT_BUG_ON(mt, mas_preallocate(&mas, GFP_KERNEL) != 0);
> allocated = mas_allocated(&mas);
> height = mas_mt_height(&mas);
> MT_BUG_ON(mt, allocated == 0);
> @@ -35558,18 +35558,18 @@ static noinline void check_prealloc(struct maple_tree *mt)
> allocated = mas_allocated(&mas);
> MT_BUG_ON(mt, allocated != 0);
>
> - MT_BUG_ON(mt, mas_preallocate(&mas, ptr, GFP_KERNEL) != 0);
> + MT_BUG_ON(mt, mas_preallocate(&mas, GFP_KERNEL) != 0);
> allocated = mas_allocated(&mas);
> height = mas_mt_height(&mas);
> MT_BUG_ON(mt, allocated == 0);
> MT_BUG_ON(mt, allocated != 1 + height * 3);
> - MT_BUG_ON(mt, mas_preallocate(&mas, ptr, GFP_KERNEL) != 0);
> + MT_BUG_ON(mt, mas_preallocate(&mas, GFP_KERNEL) != 0);
> mas_destroy(&mas);
> allocated = mas_allocated(&mas);
> MT_BUG_ON(mt, allocated != 0);
>
>
> - MT_BUG_ON(mt, mas_preallocate(&mas, ptr, GFP_KERNEL) != 0);
> + MT_BUG_ON(mt, mas_preallocate(&mas, GFP_KERNEL) != 0);
> allocated = mas_allocated(&mas);
> height = mas_mt_height(&mas);
> MT_BUG_ON(mt, allocated == 0);
> @@ -35577,25 +35577,25 @@ static noinline void check_prealloc(struct maple_tree *mt)
> mn = mas_pop_node(&mas);
> MT_BUG_ON(mt, mas_allocated(&mas) != allocated - 1);
> ma_free_rcu(mn);
> - MT_BUG_ON(mt, mas_preallocate(&mas, ptr, GFP_KERNEL) != 0);
> + MT_BUG_ON(mt, mas_preallocate(&mas, GFP_KERNEL) != 0);
> mas_destroy(&mas);
> allocated = mas_allocated(&mas);
> MT_BUG_ON(mt, allocated != 0);
>
> - MT_BUG_ON(mt, mas_preallocate(&mas, ptr, GFP_KERNEL) != 0);
> + MT_BUG_ON(mt, mas_preallocate(&mas, GFP_KERNEL) != 0);
> allocated = mas_allocated(&mas);
> height = mas_mt_height(&mas);
> MT_BUG_ON(mt, allocated == 0);
> MT_BUG_ON(mt, allocated != 1 + height * 3);
> mn = mas_pop_node(&mas);
> MT_BUG_ON(mt, mas_allocated(&mas) != allocated - 1);
> - MT_BUG_ON(mt, mas_preallocate(&mas, ptr, GFP_KERNEL) != 0);
> + MT_BUG_ON(mt, mas_preallocate(&mas, GFP_KERNEL) != 0);
> mas_destroy(&mas);
> allocated = mas_allocated(&mas);
> MT_BUG_ON(mt, allocated != 0);
> ma_free_rcu(mn);
>
> - MT_BUG_ON(mt, mas_preallocate(&mas, ptr, GFP_KERNEL) != 0);
> + MT_BUG_ON(mt, mas_preallocate(&mas, GFP_KERNEL) != 0);
> allocated = mas_allocated(&mas);
> height = mas_mt_height(&mas);
> MT_BUG_ON(mt, allocated == 0);
> @@ -35604,12 +35604,12 @@ static noinline void check_prealloc(struct maple_tree *mt)
> MT_BUG_ON(mt, mas_allocated(&mas) != allocated - 1);
> mas_push_node(&mas, mn);
> MT_BUG_ON(mt, mas_allocated(&mas) != allocated);
> - MT_BUG_ON(mt, mas_preallocate(&mas, ptr, GFP_KERNEL) != 0);
> + MT_BUG_ON(mt, mas_preallocate(&mas, GFP_KERNEL) != 0);
> mas_destroy(&mas);
> allocated = mas_allocated(&mas);
> MT_BUG_ON(mt, allocated != 0);
>
> - MT_BUG_ON(mt, mas_preallocate(&mas, ptr, GFP_KERNEL) != 0);
> + MT_BUG_ON(mt, mas_preallocate(&mas, GFP_KERNEL) != 0);
> allocated = mas_allocated(&mas);
> height = mas_mt_height(&mas);
> MT_BUG_ON(mt, allocated == 0);
> @@ -35617,21 +35617,21 @@ static noinline void check_prealloc(struct maple_tree *mt)
> mas_store_prealloc(&mas, ptr);
> MT_BUG_ON(mt, mas_allocated(&mas) != 0);
>
> - MT_BUG_ON(mt, mas_preallocate(&mas, ptr, GFP_KERNEL) != 0);
> + MT_BUG_ON(mt, mas_preallocate(&mas, GFP_KERNEL) != 0);
> allocated = mas_allocated(&mas);
> height = mas_mt_height(&mas);
> MT_BUG_ON(mt, allocated == 0);
> MT_BUG_ON(mt, allocated != 1 + height * 3);
> mas_store_prealloc(&mas, ptr);
> MT_BUG_ON(mt, mas_allocated(&mas) != 0);
> - MT_BUG_ON(mt, mas_preallocate(&mas, ptr, GFP_KERNEL) != 0);
> + MT_BUG_ON(mt, mas_preallocate(&mas, GFP_KERNEL) != 0);
> allocated = mas_allocated(&mas);
> height = mas_mt_height(&mas);
> MT_BUG_ON(mt, allocated == 0);
> MT_BUG_ON(mt, allocated != 1 + height * 3);
> mas_store_prealloc(&mas, ptr);
>
> - MT_BUG_ON(mt, mas_preallocate(&mas, ptr, GFP_KERNEL) != 0);
> + MT_BUG_ON(mt, mas_preallocate(&mas, GFP_KERNEL) != 0);
> allocated = mas_allocated(&mas);
> height = mas_mt_height(&mas);
> MT_BUG_ON(mt, allocated == 0);
> @@ -35639,14 +35639,14 @@ static noinline void check_prealloc(struct maple_tree *mt)
> mas_store_prealloc(&mas, ptr);
> MT_BUG_ON(mt, mas_allocated(&mas) != 0);
> mt_set_non_kernel(1);
> - MT_BUG_ON(mt, mas_preallocate(&mas, ptr, GFP_KERNEL & GFP_NOWAIT) == 0);
> + MT_BUG_ON(mt, mas_preallocate(&mas, GFP_KERNEL & GFP_NOWAIT) == 0);
> allocated = mas_allocated(&mas);
> height = mas_mt_height(&mas);
> MT_BUG_ON(mt, allocated != 0);
> mas_destroy(&mas);
>
>
> - MT_BUG_ON(mt, mas_preallocate(&mas, ptr, GFP_KERNEL) != 0);
> + MT_BUG_ON(mt, mas_preallocate(&mas, GFP_KERNEL) != 0);
> allocated = mas_allocated(&mas);
> height = mas_mt_height(&mas);
> MT_BUG_ON(mt, allocated == 0);
> @@ -35654,7 +35654,7 @@ static noinline void check_prealloc(struct maple_tree *mt)
> mas_store_prealloc(&mas, ptr);
> MT_BUG_ON(mt, mas_allocated(&mas) != 0);
> mt_set_non_kernel(1);
> - MT_BUG_ON(mt, mas_preallocate(&mas, ptr, GFP_KERNEL & GFP_NOWAIT) == 0);
> + MT_BUG_ON(mt, mas_preallocate(&mas, GFP_KERNEL & GFP_NOWAIT) == 0);
> allocated = mas_allocated(&mas);
> height = mas_mt_height(&mas);
> MT_BUG_ON(mt, allocated != 0);
> diff --git a/mm/mmap.c b/mm/mmap.c
> index 6445fd386f04..63a03ce1d0bb 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -473,7 +473,7 @@ static int vma_link(struct mm_struct *mm, struct vm_area_struct *vma)
> MA_STATE(mas, &mm->mm_mt, 0, 0);
> struct address_space *mapping = NULL;
>
> - if (mas_preallocate(&mas, vma, GFP_KERNEL))
> + if (mas_preallocate(&mas, GFP_KERNEL))
> return -ENOMEM;
>
> if (vma->vm_file) {
> @@ -539,7 +539,7 @@ inline int vma_expand(struct ma_state *mas, struct vm_area_struct *vma,
> /* Only handles expanding */
> VM_BUG_ON(vma->vm_start < start || vma->vm_end > end);
>
> - if (mas_preallocate(mas, vma, GFP_KERNEL))
> + if (mas_preallocate(mas, GFP_KERNEL))
> goto nomem;
>
> vma_adjust_trans_huge(vma, start, end, 0);
> @@ -712,7 +712,7 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
> }
> }
>
> - if (mas_preallocate(&mas, vma, GFP_KERNEL))
> + if (mas_preallocate(&mas, GFP_KERNEL))
> return -ENOMEM;
>
> vma_adjust_trans_huge(orig_vma, start, end, adjust_next);
> @@ -1937,7 +1937,7 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
> /* Check that both stack segments have the same anon_vma? */
> }
>
> - if (mas_preallocate(&mas, vma, GFP_KERNEL))
> + if (mas_preallocate(&mas, GFP_KERNEL))
> return -ENOMEM;
>
> /* We must make sure the anon_vma is allocated. */
> @@ -2018,7 +2018,7 @@ int expand_downwards(struct vm_area_struct *vma, unsigned long address)
> return -ENOMEM;
> }
>
> - if (mas_preallocate(&mas, vma, GFP_KERNEL))
> + if (mas_preallocate(&mas, GFP_KERNEL))
> return -ENOMEM;
>
> /* We must make sure the anon_vma is allocated. */
> @@ -2310,7 +2310,7 @@ do_mas_align_munmap(struct ma_state *mas, struct vm_area_struct *vma,
> mt_init_flags(&mt_detach, MT_FLAGS_LOCK_EXTERN);
> mt_set_external_lock(&mt_detach, &mm->mmap_lock);
>
> - if (mas_preallocate(mas, vma, GFP_KERNEL))
> + if (mas_preallocate(mas, GFP_KERNEL))
> return -ENOMEM;
>
> mas->last = end - 1;
> @@ -2678,7 +2678,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
> goto free_vma;
> }
>
> - if (mas_preallocate(&mas, vma, GFP_KERNEL)) {
> + if (mas_preallocate(&mas, GFP_KERNEL)) {
> error = -ENOMEM;
> if (file)
> goto unmap_and_free_vma;
> diff --git a/mm/nommu.c b/mm/nommu.c
> index 214c70e1d059..0befa4060aea 100644
> --- a/mm/nommu.c
> +++ b/mm/nommu.c
> @@ -602,7 +602,7 @@ static int add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
> {
> MA_STATE(mas, &mm->mm_mt, vma->vm_start, vma->vm_end);
>
> - if (mas_preallocate(&mas, vma, GFP_KERNEL)) {
> + if (mas_preallocate(&mas, GFP_KERNEL)) {
> pr_warn("Allocation of vma tree for process %d failed\n",
> current->pid);
> return -ENOMEM;
> @@ -633,7 +633,7 @@ static int delete_vma_from_mm(struct vm_area_struct *vma)
> {
> MA_STATE(mas, &vma->vm_mm->mm_mt, 0, 0);
>
> - if (mas_preallocate(&mas, vma, GFP_KERNEL)) {
> + if (mas_preallocate(&mas, GFP_KERNEL)) {
> pr_warn("Allocation of vma tree for process %d failed\n",
> current->pid);
> return -ENOMEM;
> @@ -1081,7 +1081,7 @@ unsigned long do_mmap(struct file *file,
> if (!vma)
> goto error_getting_vma;
>
> - if (mas_preallocate(&mas, vma, GFP_KERNEL))
> + if (mas_preallocate(&mas, GFP_KERNEL))
> goto error_maple_preallocate;
>
> region->vm_usage = 1;
> @@ -1358,7 +1358,7 @@ int split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
> if (!new)
> goto err_vma_dup;
>
> - if (mas_preallocate(&mas, vma, GFP_KERNEL)) {
> + if (mas_preallocate(&mas, GFP_KERNEL)) {
> pr_warn("Allocation of vma tree for process %d failed\n",
> current->pid);
> goto err_mas_preallocate;
> --
> 2.25.1
>