From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
To: akpm@linux-foundation.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v2 44/46] mm/filemap: Convert mapping_get_entry to return a folio
Date: Tue, 22 Jun 2021 13:15:49 +0100 [thread overview]
Message-ID: <20210622121551.3398730-45-willy@infradead.org> (raw)
In-Reply-To: <20210622121551.3398730-1-willy@infradead.org>
The pagecache only contains folios, so indicate that this is definitely
not a tail page. Shrinks mapping_get_entry() by 56 bytes, but grows
pagecache_get_page() by 21 bytes as gcc makes slightly different hot/cold
code decisions. A net reduction of 35 bytes of text.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
mm/filemap.c | 38 +++++++++++++++++---------------------
1 file changed, 17 insertions(+), 21 deletions(-)
diff --git a/mm/filemap.c b/mm/filemap.c
index a174f8ce87ea..7d0b51f30223 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1754,49 +1754,43 @@ EXPORT_SYMBOL(page_cache_prev_miss);
* @mapping: the address_space to search
* @index: The page cache index.
*
- * Looks up the page cache slot at @mapping & @index. If there is a
- * page cache page, the head page is returned with an increased refcount.
+ * Looks up the page cache entry at @mapping & @index. If it is a folio,
+ * it is returned with an increased refcount. If it is a shadow entry
+ * of a previously evicted folio, or a swap entry from shmem/tmpfs,
+ * it is returned without further action.
*
- * If the slot holds a shadow entry of a previously evicted page, or a
- * swap entry from shmem/tmpfs, it is returned.
- *
- * Return: The head page or shadow entry, %NULL if nothing is found.
+ * Return: The folio, swap or shadow entry, %NULL if nothing is found.
*/
-static struct page *mapping_get_entry(struct address_space *mapping,
+static struct folio *mapping_get_entry(struct address_space *mapping,
pgoff_t index)
{
XA_STATE(xas, &mapping->i_pages, index);
- struct page *page;
+ struct folio *folio;
rcu_read_lock();
repeat:
xas_reset(&xas);
- page = xas_load(&xas);
- if (xas_retry(&xas, page))
+ folio = xas_load(&xas);
+ if (xas_retry(&xas, folio))
goto repeat;
/*
* A shadow entry of a recently evicted page, or a swap entry from
* shmem/tmpfs. Return it without attempting to raise page count.
*/
- if (!page || xa_is_value(page))
+ if (!folio || xa_is_value(folio))
goto out;
- if (!page_cache_get_speculative(page))
+ if (!folio_try_get_rcu(folio))
goto repeat;
- /*
- * Has the page moved or been split?
- * This is part of the lockless pagecache protocol. See
- * include/linux/pagemap.h for details.
- */
- if (unlikely(page != xas_reload(&xas))) {
- put_page(page);
+ if (unlikely(folio != xas_reload(&xas))) {
+ folio_put(folio);
goto repeat;
}
out:
rcu_read_unlock();
- return page;
+ return folio;
}
/**
@@ -1836,10 +1830,12 @@ static struct page *mapping_get_entry(struct address_space *mapping,
struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index,
int fgp_flags, gfp_t gfp_mask)
{
+ struct folio *folio;
struct page *page;
repeat:
- page = mapping_get_entry(mapping, index);
+ folio = mapping_get_entry(mapping, index);
+ page = &folio->page;
if (xa_is_value(page)) {
if (fgp_flags & FGP_ENTRY)
return page;
--
2.30.2
next prev parent reply other threads:[~2021-06-22 12:55 UTC|newest]
Thread overview: 128+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-22 12:15 [PATCH v2 00/46] Folio-enabling the page cache Matthew Wilcox (Oracle)
2021-06-22 12:15 ` [PATCH v2 01/46] mm: Add folio_to_pfn() Matthew Wilcox (Oracle)
2021-06-23 7:49 ` Christoph Hellwig
2021-06-24 15:12 ` Matthew Wilcox
2021-06-28 6:18 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 02/46] mm: Add folio_rmapping() Matthew Wilcox (Oracle)
2021-06-23 7:56 ` Christoph Hellwig
2021-06-24 15:51 ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 03/46] mm: Add kmap_local_folio() Matthew Wilcox (Oracle)
2021-06-23 7:58 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 04/46] mm: Add flush_dcache_folio() Matthew Wilcox (Oracle)
2021-06-22 12:15 ` [PATCH v2 05/46] mm: Add arch_make_folio_accessible() Matthew Wilcox (Oracle)
2021-06-23 8:00 ` Christoph Hellwig
2021-06-24 15:57 ` Matthew Wilcox
2021-06-28 6:21 ` Christoph Hellwig
2021-06-28 14:07 ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 06/46] mm: Add folio_young() and folio_idle() Matthew Wilcox (Oracle)
2021-06-22 12:15 ` [PATCH v2 07/46] mm/workingset: Convert workingset_activation to take a folio Matthew Wilcox (Oracle)
2021-06-23 8:02 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 08/46] mm/swap: Add folio_activate() Matthew Wilcox (Oracle)
2021-06-23 8:04 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 09/46] mm/swap: Add folio_mark_accessed() Matthew Wilcox (Oracle)
2021-06-23 8:07 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 10/46] mm/rmap: Add folio_mkclean() Matthew Wilcox (Oracle)
2021-06-23 8:08 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 11/46] mm/memcg: Remove 'page' parameter to mem_cgroup_charge_statistics() Matthew Wilcox (Oracle)
2021-06-23 8:09 ` Christoph Hellwig
2021-06-25 7:58 ` Michal Hocko
2021-06-22 12:15 ` [PATCH v2 12/46] mm/memcg: Use the node id in mem_cgroup_update_tree() Matthew Wilcox (Oracle)
2021-06-23 8:12 ` Christoph Hellwig
2021-06-24 16:19 ` Matthew Wilcox
2021-06-25 8:05 ` Michal Hocko
2021-06-22 12:15 ` [PATCH v2 13/46] mm/memcg: Convert commit_charge() to take a folio Matthew Wilcox (Oracle)
2021-06-23 8:13 ` Christoph Hellwig
2021-06-25 8:11 ` Michal Hocko
2021-06-22 12:15 ` [PATCH v2 14/46] mm/memcg: Add folio_charge_cgroup() Matthew Wilcox (Oracle)
2021-06-23 8:15 ` Christoph Hellwig
2021-06-24 16:42 ` Matthew Wilcox
2021-06-25 8:22 ` Michal Hocko
2021-06-25 11:34 ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 15/46] mm/memcg: Add folio_uncharge_cgroup() Matthew Wilcox (Oracle)
2021-06-23 8:16 ` Christoph Hellwig
2021-06-25 8:25 ` Michal Hocko
2021-06-25 11:21 ` Matthew Wilcox
2021-06-25 13:21 ` Michal Hocko
2021-06-22 12:15 ` [PATCH v2 16/46] mm/memcg: Add folio_migrate_cgroup() Matthew Wilcox (Oracle)
2021-06-23 8:19 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 17/46] mm/memcg: Convert mem_cgroup_track_foreign_dirty_slowpath() to folio Matthew Wilcox (Oracle)
2021-06-23 8:21 ` Christoph Hellwig
2021-06-24 17:37 ` Matthew Wilcox
2021-06-28 6:24 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 18/46] mm/migrate: Add folio_migrate_mapping() Matthew Wilcox (Oracle)
2021-06-23 8:22 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 19/46] mm/migrate: Add folio_migrate_flags() Matthew Wilcox (Oracle)
2021-06-23 8:28 ` Christoph Hellwig
2021-06-24 17:55 ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 20/46] mm/migrate: Add folio_migrate_copy() Matthew Wilcox (Oracle)
2021-06-23 8:35 ` Christoph Hellwig
2021-06-24 18:02 ` Matthew Wilcox
2021-06-28 6:26 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 21/46] mm/writeback: Rename __add_wb_stat() to wb_stat_mod() Matthew Wilcox (Oracle)
2021-06-23 8:37 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 22/46] flex_proportions: Allow N events instead of 1 Matthew Wilcox (Oracle)
2021-06-23 8:41 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 23/46] mm/writeback: Change __wb_writeout_inc() to __wb_writeout_add() Matthew Wilcox (Oracle)
2021-06-23 8:45 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 24/46] mm/writeback: Add __folio_end_writeback() Matthew Wilcox (Oracle)
2021-06-23 9:15 ` Christoph Hellwig
2021-06-24 18:20 ` Matthew Wilcox
2021-06-28 6:33 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 25/46] mm/writeback: Add folio_start_writeback() Matthew Wilcox (Oracle)
2021-06-23 9:18 ` Christoph Hellwig
2021-06-24 18:33 ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 26/46] mm/writeback: Add folio_mark_dirty() Matthew Wilcox (Oracle)
2021-06-23 9:21 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 27/46] mm/writeback: Add __folio_mark_dirty() Matthew Wilcox (Oracle)
2021-06-23 9:27 ` Christoph Hellwig
2021-06-24 18:37 ` Matthew Wilcox
2021-06-28 6:03 ` Christoph Hellwig
2021-06-28 15:43 ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 28/46] mm/writeback: Add filemap_dirty_folio() Matthew Wilcox (Oracle)
2021-06-23 9:32 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 29/46] mm/writeback: Add folio_account_cleaned() Matthew Wilcox (Oracle)
2021-06-23 9:36 ` Christoph Hellwig
2021-06-24 20:06 ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 30/46] mm/writeback: Add folio_cancel_dirty() Matthew Wilcox (Oracle)
2021-06-23 9:39 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 31/46] mm/writeback: Add folio_clear_dirty_for_io() Matthew Wilcox (Oracle)
2021-06-23 9:43 ` Christoph Hellwig
2021-06-24 20:09 ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 32/46] mm/writeback: Add folio_account_redirty() Matthew Wilcox (Oracle)
2021-06-23 9:44 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 33/46] mm/writeback: Add folio_redirty_for_writepage() Matthew Wilcox (Oracle)
2021-06-23 9:45 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 34/46] mm/filemap: Add i_blocks_per_folio() Matthew Wilcox (Oracle)
2021-06-23 9:46 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 35/46] mm/filemap: Add folio_mkwrite_check_truncate() Matthew Wilcox (Oracle)
2021-06-23 9:47 ` Christoph Hellwig
2021-06-23 13:19 ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 36/46] mm/filemap: Add readahead_folio() Matthew Wilcox (Oracle)
2021-06-23 9:50 ` Christoph Hellwig
2021-06-24 23:46 ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 37/46] mm/workingset: Convert workingset_refault() to take a folio Matthew Wilcox (Oracle)
2021-06-23 9:52 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 38/46] mm: Add folio_evictable() Matthew Wilcox (Oracle)
2021-06-23 9:54 ` Christoph Hellwig
2021-06-24 23:50 ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 39/46] mm/lru: Convert __pagevec_lru_add_fn to take a folio Matthew Wilcox (Oracle)
2021-06-23 9:55 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 40/46] mm/lru: Add folio_add_lru() Matthew Wilcox (Oracle)
2021-06-23 9:56 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 41/46] mm/page_alloc: Add folio allocation functions Matthew Wilcox (Oracle)
2021-06-23 9:58 ` Christoph Hellwig
2021-06-25 1:06 ` Matthew Wilcox
2021-06-22 12:15 ` [PATCH v2 42/46] mm/filemap: Add filemap_alloc_folio Matthew Wilcox (Oracle)
2021-06-23 9:59 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 43/46] mm/filemap: Add filemap_add_folio Matthew Wilcox (Oracle)
2021-06-23 11:30 ` Christoph Hellwig
2021-06-25 1:57 ` Matthew Wilcox
2021-06-22 12:15 ` Matthew Wilcox (Oracle) [this message]
2021-06-23 11:32 ` [PATCH v2 44/46] mm/filemap: Convert mapping_get_entry to return a folio Christoph Hellwig
2021-06-25 3:29 ` Matthew Wilcox
2021-06-28 6:07 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 45/46] mm/filemap: Add filemap_get_folio Matthew Wilcox (Oracle)
2021-06-23 11:39 ` Christoph Hellwig
2021-06-22 12:15 ` [PATCH v2 46/46] mm/filemap: Add FGP_STABLE Matthew Wilcox (Oracle)
2021-06-23 11:43 ` Christoph Hellwig
2021-06-23 12:15 ` Matthew Wilcox
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