| From | Matthew Wilcox <> | Subject | [PATCH v9 47/61] shmem: Convert shmem_alloc_hugepage to XArray | Date | Tue, 13 Mar 2018 06:26:25 -0700 |
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From: Matthew Wilcox <mawilcox@microsoft.com>
xa_find() is a slightly easier API to use than radix_tree_gang_lookup_slot() because it contains its own RCU locking.
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> --- mm/shmem.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-)
diff --git a/mm/shmem.c b/mm/shmem.c index fb06fb3e644a..a0a354a87f3b 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1416,23 +1416,17 @@ static struct page *shmem_alloc_hugepage(gfp_t gfp, struct shmem_inode_info *info, pgoff_t index) { struct vm_area_struct pvma; - struct inode *inode = &info->vfs_inode; - struct address_space *mapping = inode->i_mapping; - pgoff_t idx, hindex; - void __rcu **results; + struct address_space *mapping = info->vfs_inode.i_mapping; + pgoff_t hindex; struct page *page; if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE)) return NULL; hindex = round_down(index, HPAGE_PMD_NR); - rcu_read_lock(); - if (radix_tree_gang_lookup_slot(&mapping->i_pages, &results, &idx, - hindex, 1) && idx < hindex + HPAGE_PMD_NR) { - rcu_read_unlock(); + if (xa_find(&mapping->i_pages, &hindex, hindex + HPAGE_PMD_NR - 1, + XA_PRESENT)) return NULL; - } - rcu_read_unlock(); shmem_pseudo_vma_init(&pvma, info, hindex); page = alloc_pages_vma(gfp | __GFP_COMP | __GFP_NORETRY | __GFP_NOWARN, -- 2.16.1
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