[patch 074/262] mm: drop first_index/last_index in zap_details

Andrew Morton
2021-11-05T20:38:34Z

From: Peter Xu <peterx@redhat.com>
Subject: mm: drop first_index/last_index in zap_details

The first_index/last_index parameters in zap_details are actually only
used in unmap_mapping_range_tree(). At the meantime, this function is
only called by unmap_mapping_pages() once. Instead of passing these two
variables through the whole stack of page zapping code, remove them from
zap_details and let them simply be parameters of
unmap_mapping_range_tree(), which is inlined.

Link: https://lkml.kernel.org/r/20210915181535.11238-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Liam Howlett <liam.howlett@oracle.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

include/linux/mm.h | 2 --
mm/memory.c | 31 ++++++++++++++++++-------------
2 files changed, 18 insertions(+), 15 deletions(-)

--- a/include/linux/mm.h~mm-drop-first_index-last_index-in-zap_details
+++ a/include/linux/mm.h
@@ -1688,8 +1688,6 @@ extern void user_shm_unlock(size_t, stru
*/
struct zap_details {
struct address_space *check_mapping; /* Check page->mapping if set */
- pgoff_t first_index; /* Lowest page->index to unmap */
- pgoff_t last_index; /* Highest page->index to unmap */
struct page *single_page; /* Locked page to be unmapped */
};

--- a/mm/memory.c~mm-drop-first_index-last_index-in-zap_details
+++ a/mm/memory.c
@@ -3325,20 +3325,20 @@ static void unmap_mapping_range_vma(stru
}

static inline void unmap_mapping_range_tree(struct rb_root_cached *root,
+ pgoff_t first_index,
+ pgoff_t last_index,
struct zap_details *details)
{
struct vm_area_struct *vma;
pgoff_t vba, vea, zba, zea;

- vma_interval_tree_foreach(vma, root,
- details->first_index, details->last_index) {
-
+ vma_interval_tree_foreach(vma, root, first_index, last_index) {
vba = vma->vm_pgoff;
vea = vba + vma_pages(vma) - 1;
- zba = details->first_index;
+ zba = first_index;
if (zba < vba)
zba = vba;
- zea = details->last_index;
+ zea = last_index;
if (zea > vea)
zea = vea;

@@ -3364,18 +3364,22 @@ void unmap_mapping_page(struct page *pag
{
struct address_space *mapping = page->mapping;
struct zap_details details = { };
+ pgoff_t first_index;
+ pgoff_t last_index;

VM_BUG_ON(!PageLocked(page));
VM_BUG_ON(PageTail(page));

+ first_index = page->index;
+ last_index = page->index + thp_nr_pages(page) - 1;
+
details.check_mapping = mapping;
- details.first_index = page->index;
- details.last_index = page->index + thp_nr_pages(page) - 1;
details.single_page = page;

i_mmap_lock_write(mapping);
if (unlikely(!RB_EMPTY_ROOT(&mapping->i_mmap.rb_root)))
- unmap_mapping_range_tree(&mapping->i_mmap, &details);
+ unmap_mapping_range_tree(&mapping->i_mmap, first_index,
+ last_index, &details);
i_mmap_unlock_write(mapping);
}

@@ -3395,16 +3399,17 @@ void unmap_mapping_pages(struct address_
pgoff_t nr, bool even_cows)
{
struct zap_details details = { };
+ pgoff_t first_index = start;
+ pgoff_t last_index = start + nr - 1;

details.check_mapping = even_cows ? NULL : mapping;
- details.first_index = start;
- details.last_index = start + nr - 1;
- if (details.last_index < details.first_index)
- details.last_index = ULONG_MAX;
+ if (last_index < first_index)
+ last_index = ULONG_MAX;

i_mmap_lock_write(mapping);
if (unlikely(!RB_EMPTY_ROOT(&mapping->i_mmap.rb_root)))
- unmap_mapping_range_tree(&mapping->i_mmap, &details);
+ unmap_mapping_range_tree(&mapping->i_mmap, first_index,
+ last_index, &details);
i_mmap_unlock_write(mapping);
}
EXPORT_SYMBOL_GPL(unmap_mapping_pages);
_