From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
For huge page we add to radix tree HPAGE_CACHE_NR pages at once: head
page for the specified index and HPAGE_CACHE_NR-1 tail pages for
following indexes.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
mm/filemap.c | 76 ++++++++++++++++++++++++++++++++++++++++------------------
1 file changed, 53 insertions(+), 23 deletions(-)
diff --git a/mm/filemap.c b/mm/filemap.c
index 2d99191..6bac9e2 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -447,6 +447,7 @@ int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
pgoff_t offset, gfp_t gfp_mask)
{
int error;
+ int nr = 1;
VM_BUG_ON(!PageLocked(page));
VM_BUG_ON(PageSwapBacked(page));
@@ -454,32 +455,61 @@ int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
error = mem_cgroup_cache_charge(page, current->mm,
gfp_mask & GFP_RECLAIM_MASK);
if (error)
- goto out;
+ return error;
- error = radix_tree_preload(gfp_mask & ~__GFP_HIGHMEM);
- if (error == 0) {
- page_cache_get(page);
- page->mapping = mapping;
- page->index = offset;
+ if (PageTransHuge(page)) {
+ BUILD_BUG_ON(HPAGE_CACHE_NR > RADIX_TREE_PRELOAD_NR);
+ nr = HPAGE_CACHE_NR;
+ }
+ error = radix_tree_preload_count(nr, gfp_mask & ~__GFP_HIGHMEM);
+ if (error) {
+ mem_cgroup_uncharge_cache_page(page);
+ return error;
+ }
- spin_lock_irq(&mapping->tree_lock);
- error = radix_tree_insert(&mapping->page_tree, offset, page);
- if (likely(!error)) {
- mapping->nrpages++;
- __inc_zone_page_state(page, NR_FILE_PAGES);
- spin_unlock_irq(&mapping->tree_lock);
- trace_mm_filemap_add_to_page_cache(page);
- } else {
- page->mapping = NULL;
- /* Leave page->index set: truncation relies upon it */
- spin_unlock_irq(&mapping->tree_lock);
- mem_cgroup_uncharge_cache_page(page);
- page_cache_release(page);
+ page_cache_get(page);
+ spin_lock_irq(&mapping->tree_lock);
+ page->mapping = mapping;
+ page->index = offset;
+ error = radix_tree_insert(&mapping->page_tree, offset, page);
+ if (unlikely(error))
+ goto err;
+ if (PageTransHuge(page)) {
+ int i;
+ for (i = 1; i < HPAGE_CACHE_NR; i++) {
+ page_cache_get(page + i);
+ page[i].index = offset + i;
+ error = radix_tree_insert(&mapping->page_tree,
+ offset + i, page + i);
+ if (error) {
+ page_cache_release(page + i);
+ break;
+ }
}
- radix_tree_preload_end();
- } else
- mem_cgroup_uncharge_cache_page(page);
-out:
+ if (error) {
+ error = ENOSPC; /* no space for a huge page */
+ for (i--; i > 0; i--) {
+ radix_tree_delete(&mapping->page_tree,
+ offset + i);
+ page_cache_release(page + i);
+ }
+ radix_tree_delete(&mapping->page_tree, offset);
+ goto err;
+ }
+ }
+ __mod_zone_page_state(page_zone(page), NR_FILE_PAGES, nr);
+ mapping->nrpages += nr;
+ spin_unlock_irq(&mapping->tree_lock);
+ trace_mm_filemap_add_to_page_cache(page);
+ radix_tree_preload_end();
+ return 0;
+err:
+ page->mapping = NULL;
+ /* Leave page->index set: truncation relies upon it */
+ spin_unlock_irq(&mapping->tree_lock);
+ radix_tree_preload_end();
+ mem_cgroup_uncharge_cache_page(page);
+ page_cache_release(page);
return error;
}
EXPORT_SYMBOL(add_to_page_cache_locked);
--
1.7.10.4
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