The patch titled
Subject: hugetlbfs: remove meaningless variable avoid_reserve
has been added to the -mm tree. Its filename is
hugetlbfs-remove-meaningless-variable-avoid_reserve.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/hugetlbfs-remove-meaningless-variable-avoid_reserve.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/hugetlbfs-remove-meaningless-variable-avoid_reserve.patch
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------------------------------------------------------
From: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Subject: hugetlbfs: remove meaningless variable avoid_reserve
The variable avoid_reserve is meaningless because we never changed its
value and just passed it to alloc_huge_page(). So remove it to make code
more clear that in hugetlbfs_fallocate, we never avoid reserve when alloc
hugepage yet. Also add a comment offered by Mike Kravetz to explain this.
Link: https://lkml.kernel.org/r/20210120071508.9078-1-linmiaohe@xxxxxxxxxx
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/hugetlbfs/inode.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
--- a/fs/hugetlbfs/inode.c~hugetlbfs-remove-meaningless-variable-avoid_reserve
+++ a/fs/hugetlbfs/inode.c
@@ -680,7 +680,6 @@ static long hugetlbfs_fallocate(struct f
*/
struct page *page;
unsigned long addr;
- int avoid_reserve = 0;
cond_resched();
@@ -716,8 +715,15 @@ static long hugetlbfs_fallocate(struct f
continue;
}
- /* Allocate page and add to page cache */
- page = alloc_huge_page(&pseudo_vma, addr, avoid_reserve);
+ /*
+ * Allocate page without setting the avoid_reserve argument.
+ * There certainly are no reserves associated with the
+ * pseudo_vma. However, there could be shared mappings with
+ * reserves for the file at the inode level. If we fallocate
+ * pages in these areas, we need to consume the reserves
+ * to keep reservation accounting consistent.
+ */
+ page = alloc_huge_page(&pseudo_vma, addr, 0);
hugetlb_drop_vma_policy(&pseudo_vma);
if (IS_ERR(page)) {
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
_
Patches currently in -mm which might be from linmiaohe@xxxxxxxxxx are
mm-hugetlb-fix-potential-double-free-in-hugetlb_register_node-error-path.patch
mm-hugetlb-avoid-unnecessary-hugetlb_acct_memory-call.patch
mm-hugetlb-use-helper-huge_page_order-and-pages_per_huge_page.patch
mm-compaction-remove-duplicated-vm_bug_on_page-pagelocked.patch
hugetlbfs-remove-useless-bug_oninode-in-hugetlbfs_setattr.patch
hugetlbfs-use-helper-macro-default_hstate-in-init_hugetlbfs_fs.patch
hugetlbfs-correct-obsolete-function-name-in-hugetlbfs_read_iter.patch
hugetlbfs-remove-meaningless-variable-avoid_reserve.patch
mm-zsmallocc-convert-to-use-kmem_cache_zalloc-in-cache_alloc_zspage.patch
