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authorMatthew Wilcox <willy@infradead.org>2017-11-27 15:46:54 -0500
committerMatthew Wilcox <willy@infradead.org>2018-10-21 10:46:37 -0400
commit8d93b41c09d1b74f376e3b9779eb3badeb550301 (patch)
treec986b3f3c82a3b9371d29d309356ab540bcd84a1 /mm/swap_state.c
parentmm: Convert truncate to XArray (diff)
downloadlinux-dev-8d93b41c09d1b74f376e3b9779eb3badeb550301.tar.xz
linux-dev-8d93b41c09d1b74f376e3b9779eb3badeb550301.zip
mm: Convert add_to_swap_cache to XArray
Combine __add_to_swap_cache and add_to_swap_cache into one function since there is no more need to preload. Signed-off-by: Matthew Wilcox <willy@infradead.org>
Diffstat (limited to 'mm/swap_state.c')
-rw-r--r--mm/swap_state.c93
1 files changed, 29 insertions, 64 deletions
diff --git a/mm/swap_state.c b/mm/swap_state.c
index ecee9c6c4cc1..850314c2c3ab 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -107,14 +107,15 @@ void show_swap_cache_info(void)
}
/*
- * __add_to_swap_cache resembles add_to_page_cache_locked on swapper_space,
+ * add_to_swap_cache resembles add_to_page_cache_locked on swapper_space,
* but sets SwapCache flag and private instead of mapping and index.
*/
-int __add_to_swap_cache(struct page *page, swp_entry_t entry)
+int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp)
{
- int error, i, nr = hpage_nr_pages(page);
- struct address_space *address_space;
+ struct address_space *address_space = swap_address_space(entry);
pgoff_t idx = swp_offset(entry);
+ XA_STATE_ORDER(xas, &address_space->i_pages, idx, compound_order(page));
+ unsigned long i, nr = 1UL << compound_order(page);
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(PageSwapCache(page), page);
@@ -123,50 +124,30 @@ int __add_to_swap_cache(struct page *page, swp_entry_t entry)
page_ref_add(page, nr);
SetPageSwapCache(page);
- address_space = swap_address_space(entry);
- xa_lock_irq(&address_space->i_pages);
- for (i = 0; i < nr; i++) {
- set_page_private(page + i, entry.val + i);
- error = radix_tree_insert(&address_space->i_pages,
- idx + i, page + i);
- if (unlikely(error))
- break;
- }
- if (likely(!error)) {
+ do {
+ xas_lock_irq(&xas);
+ xas_create_range(&xas);
+ if (xas_error(&xas))
+ goto unlock;
+ for (i = 0; i < nr; i++) {
+ VM_BUG_ON_PAGE(xas.xa_index != idx + i, page);
+ set_page_private(page + i, entry.val + i);
+ xas_store(&xas, page + i);
+ xas_next(&xas);
+ }
address_space->nrpages += nr;
__mod_node_page_state(page_pgdat(page), NR_FILE_PAGES, nr);
ADD_CACHE_INFO(add_total, nr);
- } else {
- /*
- * Only the context which have set SWAP_HAS_CACHE flag
- * would call add_to_swap_cache().
- * So add_to_swap_cache() doesn't returns -EEXIST.
- */
- VM_BUG_ON(error == -EEXIST);
- set_page_private(page + i, 0UL);
- while (i--) {
- radix_tree_delete(&address_space->i_pages, idx + i);
- set_page_private(page + i, 0UL);
- }
- ClearPageSwapCache(page);
- page_ref_sub(page, nr);
- }
- xa_unlock_irq(&address_space->i_pages);
+unlock:
+ xas_unlock_irq(&xas);
+ } while (xas_nomem(&xas, gfp));
- return error;
-}
-
-
-int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp_mask)
-{
- int error;
+ if (!xas_error(&xas))
+ return 0;
- error = radix_tree_maybe_preload_order(gfp_mask, compound_order(page));
- if (!error) {
- error = __add_to_swap_cache(page, entry);
- radix_tree_preload_end();
- }
- return error;
+ ClearPageSwapCache(page);
+ page_ref_sub(page, nr);
+ return xas_error(&xas);
}
/*
@@ -217,7 +198,7 @@ int add_to_swap(struct page *page)
return 0;
/*
- * Radix-tree node allocations from PF_MEMALLOC contexts could
+ * XArray node allocations from PF_MEMALLOC contexts could
* completely exhaust the page allocator. __GFP_NOMEMALLOC
* stops emergency reserves from being allocated.
*
@@ -229,7 +210,6 @@ int add_to_swap(struct page *page)
*/
err = add_to_swap_cache(page, entry,
__GFP_HIGH|__GFP_NOMEMALLOC|__GFP_NOWARN);
- /* -ENOMEM radix-tree allocation failure */
if (err)
/*
* add_to_swap_cache() doesn't return -EEXIST, so we can safely
@@ -414,18 +394,10 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
}
/*
- * call radix_tree_preload() while we can wait.
- */
- err = radix_tree_maybe_preload(gfp_mask & GFP_KERNEL);
- if (err)
- break;
-
- /*
* Swap entry may have been freed since our caller observed it.
*/
err = swapcache_prepare(entry);
if (err == -EEXIST) {
- radix_tree_preload_end();
/*
* We might race against get_swap_page() and stumble
* across a SWAP_HAS_CACHE swap_map entry whose page
@@ -433,26 +405,19 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
*/
cond_resched();
continue;
- }
- if (err) { /* swp entry is obsolete ? */
- radix_tree_preload_end();
+ } else if (err) /* swp entry is obsolete ? */
break;
- }
- /* May fail (-ENOMEM) if radix-tree node allocation failed. */
+ /* May fail (-ENOMEM) if XArray node allocation failed. */
__SetPageLocked(new_page);
__SetPageSwapBacked(new_page);
- err = __add_to_swap_cache(new_page, entry);
+ err = add_to_swap_cache(new_page, entry, gfp_mask & GFP_KERNEL);
if (likely(!err)) {
- radix_tree_preload_end();
- /*
- * Initiate read into locked page and return.
- */
+ /* Initiate read into locked page */
lru_cache_add_anon(new_page);
*new_page_allocated = true;
return new_page;
}
- radix_tree_preload_end();
__ClearPageLocked(new_page);
/*
* add_to_swap_cache() doesn't return -EEXIST, so we can safely